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Antimony（Sb） has high theoretical specific capacity and moderate reaction potential, but poor cycling stability and rate performance caused by large volume expansion and sluggish reaction kinetics limit its development in alkali‐ion batteries. The construction of carbon/Sb composites can solve this problem, but the traditional single carbon composite and poor Sb/carbon interface have limited promotion. Here, under the guidance of theoretical calculations, a strategy of hierarchical double carbon composite is proposed to enhance the performance of Sb anode, and systematically reveal the lithium/sodium ions (Li+/Na+) storage mechanism of Sb in complex composite system. Sb nanoparticles (Sb NPs) are encapsulated in carbon sphere matrix with strong interfacial chemical bond to form the first level composite material, and then the highly conductive and mechanically strong graphene is used as a three‐dimensional skeleton network to connect the first level composite to form the second level composite material. The hierarchical double carbon/Sb composite exhibits excellent rate (228 mAh g−1 @ 20 A g−1) and long cycling performance (373.7 mAh g−1 @ 2 A g−1 after 2200 cycles, capacity retention of 93.1%). This work may expand structural design and interface regulation of Sb/C composites and providing theoretical guidance for metal anodes development. [ABSTRACT FROM AUTHOR]

Hollow Ni 0.75 Zn 0.25 Fe 2 O 4 nanospheres with a diameter of about 250–300 nm and thickness of 30–40 nm have been successfully fabricated through a PVP (polyvinylpyrrolidone)-assisted hydrothermal strategy. PVP plays an important role in the formation of hollow structure and a plausible formation mechanism of hollow Ni 0.75 Zn 0.25 Fe 2 O 4 nanospheres is also proposed in this paper. The as-fabricated hollow Ni 0.75 Zn 0.25 Fe 2 O 4 nanospheres display a good dispersibility and high specific surface area of 34.7 m2 g−1. Hollow Ni 0.75 Zn 0.25 Fe 2 O 4 nanospheres also demonstrate satisfactory cycle life and rate performance when evaluated as a lithium ion battery negative electrode. Namely, after 120 cycles, the discharge specific capacity is 1321.3 mAh g−1 at 200 mA g−1, and the capacity retention rate is as high as 99.2%. Furthermore, the average discharge capacities are 1482.5, 1451.5, 1330.9, 1232.3, 1031.2 and 944.8 mAh g−1 under the current densities of 100, 200, 500, 1000, 2000 and 4000 mA g−1, respectively. The promising electrochemical performance of the hollow Ni 0.75 Zn 0.25 Fe 2 O 4 nanosphere could be attributed to the unique hollow structure of nanospheres, which offers a higher specific surface area and shorten transmission pathways of electrons and ions, buffering the volume expansion during the Li+ insertion/desorption process. • Hollow Ni 0.75 Zn 0.25 Fe 2 O 4 have been fabricated by a hydrothermal strategy. • PVP plays an important role in the formation of hollow structure. • Hollow Ni 0.75 Zn 0.25 Fe 2 O 4 present enhanced electrochemical performance in LIBs. [ABSTRACT FROM AUTHOR]

Copper phosphide has shown remarkable development potential in the anode materials of lithium ion batteries (LIBs) due to its high mass/volume ratio capacity. Nevertheless, the low conductivity and volumetric expansion in the cycling process restrict its practical application. Herein, we ingeniously designed and successfully prepared copper phosphide (Cu 3 P)@carbon (C) nanocomposite with multi-stage pore inverse opals (Cu 3 P@C MSPIOs), including possessed the ordered macropores with the mean aperture of ∼100 nm induced by polystyrene (PS) sphere templates and the mesoporous structure with the pore size range of 3.0-9.5 nm and 16–27 nm derived from metal-organic framework (MOF) precursor. Compared to the Cu 3 P@C particles prepared without PS sphere templates, the Cu 3 P@C MSPIOs as the anode materials demonstrated exceptional lithium storage performance. At a high current density of 2 A g-1, the discharge specific capacity of Cu 3 P@C MSPIOs was 295 mA h g-1 in the 1st cycle while that dropped to 204 mA h g-1 during the 2nd one, and then gradually stabilized. After 1500 cycles, the discharge specific capacity can still reach to 166.3 mA h g-1, maintaining 81% capacity compared to the 2nd discharge specific capacity, which indicates the Cu 3 P@C MSPIOs as the anode material presented good cycling stability. Apparently, the multi-stage pore structure, which can effectively resolve the volumetric change problem during lithium ion (Li+) intercalation/deintercalation as well as facilitate contact between electrolyte and anode, is primarily responsible of the superior Li-ion storage property of Cu 3 P@C MSPIOs. At the same time, MOF derived carbon can improve electrical conductivity, accelerate the formation of a stable solid electrolyte interface membrane and also provide buffer layers to further alleviate volumetric expansion. [ABSTRACT FROM AUTHOR]

The oxide glass‐based anodes for lithium‐ion Batteries (LiBs) still suffer from two critical drawbacks, that is, low reversible capacity and low electrical conductivity. Here, we report a new way to overcome the two drawbacks. Specifically, we chose 50Fe2O3–50P2O5 (50Fe50P) glass as the anode material for LiBs, and then thermally treat it at 1118 K (Tg+345 K) for 0.5 h under reducing atmosphere (5 mol% H2+95 mol% Ar). The thermal reduction treatment led to formation of Fe2(P4O12) and Fe2Fe5(P2O7)4 crystals. The reduced glass‐based anode for LiBs exhibits the capacity of 373 mA h g−1 after 1 000 charge/discharge cycles at 1 A g−1, which is higher than that of the oxidized one. The reduction treatment greatly lowers the charge transfer resistance in the glass anode, indicating the enhancement of the electrical conductivity. This performance improvement could arise from the increase of accessible active sites for Li+ ion storage and transfer due to the existence of crystal–crystal/crystal–glass boundaries, as well as from the improvement of the electron transfer between Fe2+ and Fe3+ during cycling. This reduction–crystallization approach could help develop high‐performance oxide glass‐ceramics based anodes for advanced LiBs. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries (LIBs) served as promising energy-storage solutions for various applications, from portable electronics to electric-vehicles. There is a growing demand for high-performance electrode materials with improved storage capacity, high cyclic stability, low energy barriers, reduced material toxicity, and cost-effectiveness. This study explores the electrochemical feasibility of B 4 C 3 monolayer as an anode material for LIBs using density functional theory (DFT) computations and molecular dynamic (MD) simulations. The optimum anodic nature of B 4 C 3 is reported based on its structural, electronic, diffusion, storage behaviour, and lithiation studies. The adsorption sites for Li atoms were systematically explored. The lithium saturation requires the adsorption of 29 lithium atoms on B 4 C 3 while preserving stability confirmed by Ab-initio molecular dynamics (AIMD) simulations and ensuring favorable transport characteristics during the lithiation process based on Hirshfeld charge analysis and steric interaction calculations. The storage capacity of the host B 4 C 3 is calculated as 2770.2 mAhg−1 which is notably higher than that of graphite anode. The computed value of open circuit voltage is 0.62 V per Li. The value of diffusion coefficient and ionic conductivity σ is 0.7 × 10−8 m2/s and 0.78 S/m respectively which predicts excellent overall anodic operation of the material. The transition barrier of the Li ions in the material is determined through Cl-NEB, which shows the lowest value of 0.06 eV along the x-axis. Highlights of the work: Following are key highlights of the work. • Density Functional Theory (DFT) of B 4 C 3 as anode for lithium-ion batteries. • Dynamical and thermal stability • Electronic properties to explore conductivity and charge transfer characteristics • Storage capacity is 2770 mAhg−1 • Diffusion kinetics of lithium ions in the lattice • Electrochemical performance as anode materials [ABSTRACT FROM AUTHOR]

The ever-increasing worldwide energy demand and the limited resources of fossil have forced the urgent adoption of renewable energy sources. Additionally, concerns over CO2 emissions and potential increases in fuel prices have boosted technical efforts to make hybrid and electric vehicles more accessible to the public. Rechargeable batteries are undoubtedly a key player in this regard, especially lithium ion batteries (LIBs), which have high power capacity, a fast charge/discharge rate, and good cycle stability, while their further energy density improvement has been severely limited, because of the relatively low theoretical capacity of the graphite anode material which is mostly used. Among various high-capacity anode candidates, tin (II) sulfide (SnS2) has been attracted remarkable attention for high-energy LIBs due to its enormous resource and simplicity of synthesis, in addition to its high theoretical capacity. However, SnS2 has poor intrinsic conductivity, a big volume transition, and a low initial Coulombic efficiency, resulting in a short lifespan. SnS2/carbon composites have been considered to be a most promising approach to addressing the abovementioned issues. Therefore, this review summarizes the current progress in the synthesis of SnS2/carbon anode materials and their Li-ion storage properties, with special attention to the developments in Li-based technology, attributed to its immense current importance and promising prospects. Finally, the existing challenges within this field are presented, and potential opportunities are discussed. [ABSTRACT FROM AUTHOR]

Tin dioxide (SnO 2) is a promising anode material for lithium-ion and sodium-ion batteries. However, the huge volume expansion during cycling makes it far away from practical application. Herein, we report a template-free "heterogeneous carbonization" strategy for fabricating SnO 2 /carbon/void/carbon nanofibers (SCVC) compound membrane with finite spatial domain in carbon matrix as buffer layer for volume changes of SnO 2. Reduced graphene oxide (rGO) is also imported into the SCVC membrane, acting as conductive binders to construct a free-standing SCVC-rGO electrode with exceptionally conductive network. The resultant SCVC-rGO anodes in lithium/sodium-ion batteries could deliver excellent electrochemical performances of higher reversible capacity, longer lifespan and superior rate capability. As lithium-ion battery anode, the SCVC-rGO electrode shows specific capacities of 950 mA h g−1 after 400 cycles at a current of 0.5 A g−1, and 824 mA h g−1 after 650 cycles at 1 A g−1. In sodium-ion batteries, the SCVC-rGO electrode gives rise to the specific capacity of 407 mA h g−1 after 2000 cycles at the current of 1 A g−1 with exceptional capacity retention. SnO 2 /carbon/void/carbon nanofibers membrane combined with reduced graphene oxide (SCVC-rGO) is constructed by a template free, one-step heterogeneous carbonization strategy. The internal void formed in situ in SnO 2 /C can be used as confined space to accommodate its volume expansion, while the residual ultrathin carbon layer on SnO 2 nanocrystals can prevent their amalgamation and recrystallization. The SCVC-rGO anodes exhibit excellent cycling stability and rate capability in LIBs and SIBs. [Display omitted] • One-step strategy of heterogenous carbonization to in-situ form buffering voids. • Based on the different carbon yields from various precursors and without the help of templates and corrosives. • Internal voids and residual ultrathin carbon layer ensure the complete reversibility of electrochemical reactions. • Excellent cycling stability and rate capability in half cells of LIBs and SIBs have been achieved. [ABSTRACT FROM AUTHOR]

ZnSe has got extensive attention for high‐performance LIBs anode due to its remarkable theoretical capacity and environmental friendliness. Nevertheless, the large volume variation for the ZnSe in the discharge/charge processes brings about rapid capacity fading and poor rate performance. Herein, ZnSe/C hollow polyhedrons are successfully synthesized by selenization of zeolitic imidazolate framework‐8 (ZIF‐8) with resorcinol‐formaldehyde (RF) coating. The protection of C layer derived from RF coating layer and Ostwald ripening during the process of selenization play important roles in promoting formation of ZnSe/C hollow polyhedrons. The ZnSe/C hollow polyhedrons exhibit good rate performance and long‐term cycle stability (345 mAh g−1 up to 1000 cycles at 1 A g−1) for lithium ion batteries (LIBs) anode. The improved electrochemical performance is benefit from the unique ZnSe/C hollow structure, in which the hollow structure can effectively avoid terrible volume expansion, and the thin ZnSe/C shell can not only provide adequate diffusion paths of lithium ions and but also enhance the electronic conductivity. [ABSTRACT FROM AUTHOR]

Ethanol, deionised water and their mixture were used as the ball-milling solvents to prepare Fe2SiO4/C nanocomposites via solid-state reactions from ferrous oxalate, nano silica and ammonium citrate. The three Fe2SiO4/C nanocomposites are orderly designated as FS/C-E, FS/C-W and FS/C-M and exhibit different structure. XRD results indicate that all three Fe2SiO4/C nanocomposites are fayalite crystal phase and FS/C-M has developed (111) lattice planes. SEM results further indicate that FS/C-M has the smallest particle size among the three Fe2SiO4/C nanocomposites. TEM also results indicate that Fe2SiO4 nanoparticles are evenly dispersed the carbon networks of FS/C-M. These unique structure ensure FS/C-M deliver a high charge capacity of 718.3 mAh/g at 0.1 C, high rate performance (391.6 mAh/g at 5 C) and good cycling performance (707.4 mAh/g at 1 C after 200 cycles). [ABSTRACT FROM AUTHOR]

The unbearable volume expansion of silicon hinders its application for lithium-ion batteries (LIBs). The utilization of carbon coating to silicon has significantly improved its performance. However, the carbon coatings prepared via traditional methods are often too fragile to prevent the carbon-silicon electrode from pulverization during the long-term cycling process. Herein, a new, convenient, low-cost method is developed to prepare silicon-nickel-carbon composites with high mechanical strength and ion diffusivity for LIBs. Graphenic carbon network materials embedded with Si and Ni nanoparticles are prepared by using in-situ generated Ni0 as catalysts to the thermal polymerization of polycyclic asphalt molecules. The composites show excellent LIB performance, superior to those prepared conventionally without the addition of nickel. The composite with 73.7 wt% Si shows an initial Coulombic efficiency of 87.5% and a charge capacity of 3191 mA h g−1. The electrode expands only 16.5% in thickness after cycled 300 times at 2 A g−1. Moreover, the composites with 19.6 wt% and 33.8 wt% Si exhibit capacities of 342 and 680 mA h g−1 after cycled 500 times at 2 A g−1, with capacity retention of 97% and 85%, respectively. The results show that the present method is promising for the preparation of stable silicon-carbon anode materials. [Display omitted] [ABSTRACT FROM AUTHOR]

Sn@Graphene composites as anode materials in Lithium-ion batteries have attracted intensive interest due to the inherent high capacity. On the other side, the high atomic ratio (Li 4.4 Sn) induces the pulverization of the electrode with cycling. Thus, suppressing pulverization by designing the structure of the materials is an essential key for improving cyclability. Applying the nanotechnologies such as electrospinning, soft/hard nano template strategy, surface modification, multi-step chemical vapor deposition (CVD), and so on has demonstrated the huge advantage on this aspect. These strategies are generally used for homogeneous dispersing Sn nanomaterials in graphene matrix or constructing the voids in the inner of the materials to obtain the mechanical buffer effect. Unfortunately, these processes induce huge energy consumption and complicated operation. To solve the issue, new nanotechnology for the composites by the bottom-up strategy (Organic Molecule Confinement Reaction (OMCR)) was shown in this report. A 3D organic nanoframes was synthesized as a graphene precursor by low energy nano emulsification and photopolymerization. SnO 2 nanoparticles@3D organic nanoframes as the composites precursor were in-situ formed in the hydrothermal reaction. After the redox process by the calcination, the Sn nanoparticles with nanovoids (~100 nm, uniform size) were homogeneously dispersed in a Two-Dimensional Laminar Matrix of graphene nanosheets (2DLM G) by the in-situ patterning and confinement effect from the 3D organic nanoframes. The pulverization and crack of the composites were effectively suppressed, which was proved by the electrochemical testing. The Sn nanoparticles@2DLM G not delivered just the high cyclability during 200 cycles, but also firstly achieved a high specific capacity (539 mAh g−1) at the low loading Sn (19.58 wt%). [ABSTRACT FROM AUTHOR]

Ti/Fe substitution in ramsdellite LiTi 2 O 4 , an attractive insertion material for lithium-ion battery applications, has been performed by the ceramic method yielding electrode materials with general stoichiometry LiFe x Ti 2−x O 4. Samples with 0 ≤ x ≤ 0.5 resulted in well crystallized orthorhombic ramsdellite phases, space group Pbnm , while samples with x > 0.5 formed spinel, space group Fd -3 m , as revealed by powder X-ray diffraction. The ramsdellites were further investigated with X-EDS microanalysis, 57Fe Mössbauer spectroscopy and electrochemical discharge-charge cycling in lithium cells. This provided a comprehensive insight into the Ti/Fe substitution mechanism, which turned out to be rather more complex than the predicted simple M3+ isovalent substitution, with participation of Fe3+/Fe2+ and Ti4+/Ti3+. Upon testing against lithium in the low voltage range (ocv -1 V), ramsdellite with low Ti/Fe substitution, namely LiFe 0.125 Ti 1.875 O 4 , outperformed undoped LiTi 2 O 4 electrochemically, delivering a 1st cycle capacity of 180 mAh g−1 at C/30 (5.3 mA g−1) stabilized at 140 mAh g−1 upon cycling, compared to 120 and 80 mAh g−1, respectively, in LiTi 2 O 4. Two active redox pairs, Ti4+/Fe3+ and Fe3+/Fe2+, combined with better electrical properties due to the presence of metallic iron, boosting farther electronic conductivity in LiFe 0.125 Ti 1.875 O 4 , allow a noticeable capacity of 71 mAh g−1 still to be held at a high current of 2 C (320 mA g−1). In the high voltage range (ocv -4 V), LiFe 0.125 Ti 1.875 O 4 electrochemically outmatched the higher Fe-substituted ramsdellites, which were characterized by a high irreversible capacity ascribed to the unavailability of Fe3+/Fe4+ redox couple and electrolyte decomposition. [Display omitted] • Fe-substituted LiFe x Ti 2−x O 4 orthorhombic ramsdellites with 0 ≤x ≤ 0.5 synthesized. • Ti/Fe substitution mechanism involves Fe3+/Fe2+ and Ti4+/Ti3+ redox couples. • Reversible Fe3+/Fe2+ redox couple in ramsdellites with higher Fe content, in contrast to other iron substituted titanates. • Low Fe substitution produces significant improvement of capacity upon cycling (up to +75%) when used in lithium batteries. • Very much improved C rate behavior at all C rates up to 2 C. [ABSTRACT FROM AUTHOR]

Chromium-based transition metal sulfide such as chromium hemi trisulfide (Cr 2 S 3) gradually emerges as a potential lithium-ion host material considering its relatively large specific capacity along with low cost advantage. However, some excruciating issues such as serious particle aggregation, large volume expansion and insufficient inherent conductivity always result in an inferior Li-storage behavior such as low reversible capacity, limited cycling life and poor high-rate performance. Rational structure design and effective combination with suitable component are crucial to achieve superior Li-storage performance. Herein, a heterostructured composite with small Cr 2 S 3 nanosheets embedded into phenanthroline-derived N-doped porous carbon skeleton (Cr 2 S 3 /NC) has been synthesized through a calcination and sulfuration route. In as-prepared Cr 2 S 3 /NC composite, Cr 2 S 3 nanosheets are well confined by carbon matrix, which is conductive to an effective suppression on aggregation and volume change. Meanwhile, porous conductive carbon framework supplies desirable expressway for fast electron delivery and reduces the distance for lithium ions diffusion. Consequently, the Cr 2 S 3 /NC anode delivers a remarkably elevated Li-storage performance. • Cr 2 S 3 /NC composite with a hierarchical porous structure was fabricated via a facile annealing route. • Cr 2 S 3 nanosheets in composite were anchored on the phenanthroline-derived nitrogen-doped carbon sheets. • The composite demonstrated an enhanced Li-storage property. [ABSTRACT FROM AUTHOR]

Silicon dioxide with high-capacity and abundant resource is regarded as a promising anode material for lithium-ion batteries, but the poor intrinsic electrical conductivity and large volume change during the discharge/charge cycles impede its practical application. Herein, a three-dimensional porous composite of Ti 3 C 2 T x @SiO 2 was fabricated with a low-temperature liquid phase method, and the ratio of SiO 2 and Ti 3 C 2 T x was regulated. The as-prepared A-MX@SiO 2 -2 with the optimal composition exhibits the best cycle performance (437.9 mAh g−1 after 1000 cycles at 0.1 A g−1) and rate performance (130.0 mA h g−1 at 2 A g−1), which are much higher than pure SiO 2 and MXene. The excellent electrochemical performance can be ascribed to the synergistic effect of ultrafine SiO 2 nanoparticles and three-dimensional porous Ti 3 C 2 T x , which can shorten the Li+ transport pathway, accelerate electron transfer, and relieve the stress caused by the volume expansion of SiO 2. The composite structure effectively inhibits both the aggregation of SiO 2 and restacking of Ti 3 C 2 T x. Furthermore, the in-situ formed SiO 2 can firmly anchored on the surface of Ti 3 C 2 T x nanosheet by robust interfacial bonding, which enhances the structural stability and conductivity. This research provides a feasible design strategy for synthesis of Ti 3 C 2 T x @SiO 2 composite to be employed as advanced energy storage materials. [Display omitted] • The Ti 3 C 2 T x @SiO 2 composite with three-dimensional porous structure was obtained. • The composite effectively inhibits both the aggregation of SiO 2 and restacking of Ti 3 C 2 T x. • The in-situ formed SiO 2 firmly bonded with Ti 3 C 2 T x nanosheet enhances the structural stability and conductivity. • The ratio of SiO 2 and MXene has great influence in lithium storage performance. [ABSTRACT FROM AUTHOR]

Nano-structuring is the most optimized strategy for the kinetics acceleration of electrode materials in addressing the problems such as sluggish ion diffusion, poor electric conduction and liable pulverization. However, the complicated de-sizing methods are not preferable in future scale-up attempts, and the aggregation still needs to be solved. Herein, a facial ion-exchange/carbonization strategy is developed by tutoring the dispersion of metal ions with strong ionic interaction within resin framework, and nano-disperse of metal/metal-oxide particles (denoted as MO x) are in-situ implanted in hierarchical porous graphic carbon (HPGC). The HPGC can acts as a conductive and robust framework to anchor the MO x , while the nano-dispersed MO x can further propel the kinetics and alleviate the stress during cycling. We demonstrated the concept of this strategy via Fe 3 O 4 @HPGC and Co 3 O 4 @HPGC as representatives, both of which show superior rate capability (797.8 mAh g−1 for Co 3 O 4 @HPGC at 5 A g−1) with long cycling stability, and high areal capacity (4.65 mAh cm−2 for Co 3 O 4 @HPGC). With the industrial raw material of resin, the low cost and feasible method, this strategy can be potential candidate for the scalable synthesis of various carbon-hybridized composite materials. [Display omitted] • A novel ion-exchange strategy for design of MO x @HPGC anode was proposed. • Rational porous creation and in-situ implantation of nanoparticles were achieved. • Superior rate capability and long cycling stability of MO x @HPGC were realized. • This strategy is qualified for scalable synthesis of various carbon-based anodes. [ABSTRACT FROM AUTHOR]

A new covalent organic framework is synthesized and used as an anode material for lithium-ion batteries for the first time. Both the imine bond (C=N) and aromatic C=C bond of the TAACOF can store lithium ions reversibly, a total of up to 14 electrons participating in the redox reaction, corresponding to a high theoretical capacity of 1330.8 mAh/g. [Display omitted] • A novel covalent organic framework is synthesized under mild conditions. • The covalent organic framework is used as the anode for lithium ion batteries. • A total of up to 14 electrons are involved in the redox reaction. • Both the C = N and aromatic C = C bond can store lithium ions reversibly. • A high capacity of 1035.7 mAh g−1 is obtained after 800 cycles at 500 mA g−1. Covalent organic frameworks (COFs) have been widely used in various fields due to their abundant elemental resources, easy structure control, and abundant tunable porous structures. COFs containing electroactive organic groups with reversible redox behavior are potential electrode materials for next-generation high-performance lithium-ion batteries (LIBs). However, the aromatic conjugated structure of the backbone moiety in most reported COFs cannot participate in redox reactions, resulting in low capacity of COFs. At the same time, the synthesis processes of COFs are usually complicated and generally requires high temperature and high pressure. On this basis, an imine bond-rich COF (TAACOF) with reversible Li-ion bonding is developed, which has the advantages of facile preparation and low energy consumption. In particular, the lone pair electrons of the N atom in the imine bond can induce lithium ions to combine with the aromatic conjugated structure, which greatly improves the capacity of the TAACOF electrode. After 800 cycles, the active sites of the TAACOF are fully activated, and after a 14-electron redox reaction, the specific capacity can reach as high as 1035.7 mAh/g. [ABSTRACT FROM AUTHOR]

Mesoporous hollow hierarchical structures play an important role in enhancing the lithium storage performances of Co 3 O 4 anode materials. In this work, Co 3 O 4 with mesoporous hollow structure has been successfully fabricated by simple impregnation and subsequently air calcination using poplar branch as bio-template. The product calcined at 600 °C (PB-Co 600) perfectly duplicates the 3D aligned microchannels structure of poplar branch. Importantly, the wall of aligned microchannels in PB-Co 600 is constructed by a lot of irregular cross-linked Co 3 O 4 nanoparticles and there are abundant mesopores on the surface. As an anode, it exhibits high reversible capacity and remarkable long-cycle stability. At 0.1 A g-1, it can deliver a high specific capacity of 1153.7 mA h g-1 after 100 cycles, and even at 1 A g-1, the reversible specific capacity of 555.7 mA h g-1 can be retained after cycling 1000 times. The excellent lithium storage performance of PB-Co 600 may be attributed to its unique hierarchical structure, which is not only favorable to the rapid transfer of substances and Li+ ion diffusion, but also alleviates the volume change during the charge/discharge cycle. Furthermore, the existence of oxygen vacancies and pseudo-capacitance also contributes significantly to the superior lithium storage performance of the PB-Co 600 electrode. Therefore, the PB-Co 600 prepared by a large-scale and eco-friendly route can be used as a potential candidate anode for LIBs. Image 1 [ABSTRACT FROM AUTHOR]

Due to advantages such as low environmental impact, low price, and high theoretical specific capacity, Co3O4 has been widely studied. However, its low conductivity and volume expansion during the charging and discharging processes caused pulverization and agglomeration ultimately leads to a rapid decline in battery capacity during the cycle. The creation of nano structured composite of carbon materials and Co3O4 can be used to form a highly conductive matrix that improves the electronic conductivity, and improves the dispersion of Co3O4 to reduce agglomeration and volume expansion. In this work, the rigid conjugated plane structure of 1,10‐phenanthroline was selected to coordinated with cobalt nitrate to form a precursor complex. After heating, the crystal core of Co3O4 becomes more uniform in size with a more regular geometry. Additionally, a calcining temperature of 350 °C was shown to result in an optimal amount of carbon residue that improved electronic conductivity of the whole composite while not excessively hindering lithium‐ion transport. As a result, these properties improved the electron conductivity and protect the crystals from damage caused by volume change during charge and discharge to a certain extent, thus contributing to improved electrochemical performance. [ABSTRACT FROM AUTHOR]

Ti02 : Sm3+ nanocrystals were synthesized by solvothermal method with Sm (N03) 3 • 6H20 and tetrabutylitanate as raw materials, anhydrous ethanol and acetylacetone as solvent. Compared with Ti0 2, Sm3+ doping can reduce the volume expansion and improve the structural stability of the materials during charging and discharging. The results show that Ti02 : Sm3+ nanocrystals, as the anode material of lithium ion batteries, exhibit a high initial specific discharge capacity of 52 9. 3 m Ah / g at 1 A/ g. After 100 cycles, the capacity stabilizes at 92 _ 8 mAh/ g and the coulombic efficiency retain above 85% after the second cycle, displaying a superior cycling stability. [ABSTRACT FROM AUTHOR]

Single-walled carbon nanotube (SWCNT) wrapped GeO2/ZnWO4 nanocomposite was prepared by single-step solvothermal method. In this work, GeO2/ZnWO4 nanocomposites were prepared by varying the molar percentage of GeO2 and by further adding SWCNT for the composite to boost the electrochemical performance. The prepared GeO2/ZnWO4 nanocomposites and GeO2/ZnWO4@CNT nanocomposite are used as anode material for lithium-ion battery (LIB). As expected, GeO2/ZnWO4@CNT nanocomposite exhibits higher capacities and good rate capability than the GeO2/ZnWO4 nanocomposite. The GeO2/ZnWO4@CNT nanocomposite exhibits 930 mAh g−1 discharge capacity and 533 mAh g−1 charge capacity for the initial cycle at 100 mAh g−1 in the voltage range of 0.01–3 V (vs. Li+/Li). Even at high current density of 500 mAh g−1, GeO2/ZnWO4@CNT nanocomposite shows 231 mAh g−1 and 257 mAh g−1 charge/discharge capacity which are higher than that of GeO2/ZnWO4 nanocomposite. The GeO2/ZnWO4@CNT nanocomposite delivers 75.8% capacity retention and 100% coulombic efficiency even after 400 cycles at 300 mAh g−1. These results direct that GeO2/ZnWO4@CNT nanocomposite is a good negative electrode for lithium-ion battery. [ABSTRACT FROM AUTHOR]

Poor rate and cycling performance are the most critical drawbacks for Si-based anodes on account of their inferior conductivity and colossal volumetric expansion during lithiation/delithiation. Here we report the fabrication of structurally-integrated urchin-like Si anode, which provides prominent structural stability and distinguished electron and ion transmission pathways for lithium storage. The inexpensive solid Si waste from organosilane industry after acid-washed and further ball-milling serves as the pristine Si-source in this work. Carbon nanotubes (CNTs) are in-situ grown outside Si microparticles, resulting in an urchin-like structure (Si/CNTs). The optimized Si/CNTs presents ascendant invertible capacity and rate performance, achieving up to 920 mAh g−1 beyond 100 cycles at 100 mA g −1, and a capacity of 606.2 mAh g−1 at 1 A g −1 after long cycling for 1000 cycles. The proposed scalable synthesis can be adopted to advance the performance of other electrode materials with inferior conductivity and enormous volume expansions during cycling. [ABSTRACT FROM AUTHOR]

Heterostructure engineering of electrode materials, which is expected to accelerate the ion/electron transport rates driven by a built‐in internal electric field at the heterointerface, offers unprecedented promise in improving their cycling stability and rate performance. Herein, carbon nanotubes with Co9S8/ZnS heterostructures embedded in a N‐doped carbon framework (Co9S8/ZnS@NC) have been rationally designed via an in‐situ vapor chemical transformation strategy with the aid of thiophene, which not only acted as carbon source for the growth of carbon nanotubes but also as sulfur source for the sulfurization of metal Zn and Co. Density functional theory (DFT) calculation shows an about 3.24 eV electrostatic potential difference between ZnS and Co9S8, which results in a strong electrostatic field across the interface that makes electrons transfer from Co9S8 to the ZnS side. As expected, a stable cycling performance with reversible capacity of 411.2 mAh g−1 at 1000 mA g−1 after 300 cycles, excellent rate capability (324 mAh g−1 at 2000 A g−1) and a high percentage of pseudocapacitance contribution (87.5% at 2.2 mv/s) for lithium‐ion batteries (LIBs) are achieved. This work provides a possible strategy for designing multicomponent heterostructural materials for application in energy storage and conversion fields. [ABSTRACT FROM AUTHOR]

Owing to the high specific capacity and energy density, metal oxides have become very promising electrodes for lithium‐ion batteries (LIBs). However, poor electrical conductivity accompanied with inferior cycling stability resulting from large volume changes are the main obstacles to achieve a high reversible capacity and stable cyclability. Herein, a facile and general approach to fabricate SnO2, Fe2O3 and Fe2O3/SnO2 fibers is proposed. The appealing structural features are favorable for offering a shortened lithium‐ion diffusion length, easy access for the electrolyte and reduced volume variation when used as anodes in LIBs. As a consequence, both single and hybrid oxides show satisfactory reversible capacities (1206 mAh g−1 for Fe2O3 and 1481 mAh g−1 for Fe2O3/SnO2 after 200 cycles at 200 mA g−1) and long lifespans. [ABSTRACT FROM AUTHOR]

Ta2O5 is one of the promising anode materials for lithium ion battery application undergoing conversion reaction in combination with an extrinsic pseudocapacitance property. We have synthesized Ta2O5 nanoparticles by hydrothermal method using and without using polyethylene glycol (PEG) as co-solvent. Ta2O5 nanoparticles were characterized by PXRD, SEM, EDAX, BET, and TEM analysis. Electrochemical characterizations like Cyclic voltammetry, galvanostatic charge-discharge process, and rate capability were studied for Ta2O5 NPs. A reversible capability of 130 mA h g−1 is retained after 85 cycles at 0.1C rate by Ta2O5 NPs synthesized using PEG, and reversible capability of 127 mA h g−1 is retained after 40 cycles at 0.1C rate by Ta2O5 NPs synthesized without using PEG. Polyethylene glycol as cosolvent induced enhanced porosity favoring the fast lithium ion transport and better reversible capacity upon cycling. [ABSTRACT FROM AUTHOR]

Manganese monoxide (MnO) is a promising anode material for lithium ion batteries, but it often shows poor electrochemical performance due to some inevitable drawbacks including intrinsic low electrical conductivity, poor stability, and severe polarization. In this work, a 1D core‐shell MnO@S, N co‐doped carbon material (MnO@SNC) was obtained by pyrolysis of MnO2@PPy precursor at 600 °C in N2 atmosphere. When evaluated as an anode for lithium ion batteries, the unique structure and composition advantages endow the as‐formed material with excellent lithium storage performance in terms of high specific capacity (955.5 mAh g−1 at a current density of 500 mA g−1), long‐term cycling stability (up to 500 cycles), and superior rate capability (458.7 mAh g−1 at a current density of 2 A g−1). The outstanding electrochemical performance could be attributed to the unique 1D core‐shell structure, abundant graphited carbon and MnO nanorods. [ABSTRACT FROM AUTHOR]

Abstract Here, a high entropy oxide (HEO), Mg 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 O, was explored as an anode material for lithium ion batteries. The HEO anode provides a high initial discharge specific capacity of about 1585 mAh g−1 and exhibits superior cycling stability. A reversible capacity of 920 mAh g−1 was achieved at 100 mA g−1 after 300 cycles. Ex situ scanning electron microscopy (SEM) and selected-area electron diffraction (SAED) revealed that the surface morphology and microstructure of the HEO anodes were still stable even after long term cycling. The well-mixed cations together with an inactive material (MgO, formed after the initial discharge process) in the HEO anodes result in a remarkable cycling, rate performance and an applicable reversible capacity with an average voltage of ∼0.85 V. This work may provide a convenient method for obtaining component-controlled oxide nanostructured materials with high electrochemical performance. Graphical abstract Image 1 Highlights • High entropy oxide was explored as an anode material for lithium ion batteries. • Well-mixed cations together with the inactive material result in a remarkable cycling performance. • A reversible capacity of 920 mAh g−1 can be achieved after 300 cycles. [ABSTRACT FROM AUTHOR]

Abstract Sn-based materials are one promising high-capacity anode material for lithium-ion batteries. The practical application of Sn-based materials is generally restricted by their significant capacity fading due to the volume expansion and structural changes during Sn alloying/dealloying process. In this work, Sn-SnO 2 hybrid nanoclusters are embedded into carbon nanotube network, forming a Sn-SnO 2 @CNT composite. The Sn-SnO 2 nanoclusters are consisted of interconnected Sn and SnO 2 nanocrystals, in which SnO 2 forms a beneficial environment for the alloying/dealloying of Sn. The ultrafine particle size of SnO 2 (<10 nm) also allows a highly reversible conversion reaction, contributing to high overall capacities. The Sn-SnO 2 nanoclusters are uniformly dispersed in CNT matrix, therefore providing abundant active sites for Li-ion storage. The CNT matrix functions in improving electrical conductivity, preventing Sn aggregation, and accommodating Sn volume change in prolonged cycles. As a result, the hybrid Sn-SnO 2 @CNT electrode shows excellent rate capability (1059 mAh g−1 at 1 A g−1 and 960 mAh g−1 at 5 A g−1, corresponding to 0.53 mAh cm−2 at 0.5 mA cm−2 and 0.48 mAh cm−2 at 2.5 mA cm−2) and outstanding cycling stability (86% capacity retention after 1000 cycles at 0.5 A g−1), making it an promising anode material for high-performance lithium-ion batteries. Highlights • Sn-SnO 2 hybrid nanoclusters are loaded onto conductive CNTs via facile methods. • Reversible alloying reactions are achieved in Sn with small mechanical crushing. • The Sn-SnO 2 @CNT composite delivered significantly increased performances. [ABSTRACT FROM AUTHOR]

Abstract Under over-increasing demand of advanced lithium-ion batteries (LIBs) for long-range electric vehicles (EVs), high-capacity transition metal oxide (TMO) negative electrodes for LIBs are thought as potential substitutes of traditional graphite anodes. A major barrier for TMO anodes is volumetric expansion during lithiation processes, leading to active material pulverization and falling off current collectors, which seriously deteriorates capacity retention. Herein, apart from conventional mechanical degradation, another capacity fading mechanism is revealed. Furthermore, the understanding is supported by an interesting cycling property. Firstly, NiCo 2 O 4 with designed morphologies of nanoplates and microspheres are studied for the initial (de)lithiation and prolonged cycles. The morphology changes indicate solid electrolyte interphase (SEI) layer accumulating on the surface of electrodes and impeding the contact and reactions between lithium and active materials with a result of severe capacity loss. It can be understood as SEI layer insulating NiCo 2 O 4 , and if SEI film appropriately changes, high capacities can recovery. This conjecture is confirmed by following research of NiCo 2 O 4 nanoparticles with amazing cycling performance prepared by a facile water-bath method. As LIB anodes, NiCo 2 O 4 nanoparticles exhibit capacities of 1144 mAh g−1 at the initial discharging, 230 mAh g−1 at the 100th cycle and 661 mAh g−1 at the 500th cycle. The corresponding coulombic efficiency is of 73.1%, 98.4% and 99.5%, respectively. By TEM characterization in combination with electrochemical analysis, size-dependent SEI layer reactivation (from thick and unstable to thin and stable) is a key role on the dramatic capacity recovery. [ABSTRACT FROM AUTHOR]

Abstract Red phosphorus (P) represents one kind of high-capacity anodes for lithium ion batteries. Practical application of red P is primarily limited by its low conductivity, severe volume expansion and consequent sluggish electrode kinetics. Herein, we propose a P-TiO 2 @CNT composite with TiO 2 -modified red P nanosheets well entangled in carbon nanotube (CNT) network. The co-incorporation of amorphous TiO 2 and CNT can synergistically provide dual accommodation to red P, which not only allow its lithiation and volume expansion to exhibit high capacities, but also buffer the stress during red P expansion and avoid structural destruction. Meanwhile, the CNTs support a highly conductive skeleton and porous framework in the composite, which continuously provides high conductivity and creates more active sites for lithium storage during repeated electrochemical reactions. The P-TiO 2 @CNT electrode exhibits impressive cycling stability (87% capacity retention in 200 cycles at 0.2 A g−1) and excellent rate capability (750 mAh g−1 at 10 A g−1), making it a promising anode material for high-capacity and high-rate lithium-ion batteries. Graphical abstract Amorphous red P sheets were modified by amorphous TiO 2 and entangled into a CNT network, forming a P-TiO 2 @CNT composite with high specific capacity, large reversibility and favorable high-rate performance. Image 1 Highlights • Amorphous TiO 2 nanoparticles were decorated on red phosphorus sheets to form hybrid P-TiO 2 sheets. • P-TiO 2 sheets were entangled into well-dispersed CNT network. • The P-TiO 2 @CNT anode displayed enhanced electrochemical performance for lithium ion batteries. [ABSTRACT FROM AUTHOR]

Abstract Transition metal hydroxides are recently investigated due to its higher capacity than that of relative oxides for lithium storage in lithium ion batteries. Here, sheet-stacking Ni(OH) 2 /graphene compound is synthesized by a facile stirring solvothermal method. The as-prepared Ni(OH) 2 in the compound is proved to be β-Ni(OH) 2 and large BET specific surface area of 53.9 m2 g−1 is obtained with a total pore volume of 0.218 cm2 g−1. The graphene sheet in the sheet-stacking structure not only offers fast electronic transfer through carbon meshwork, but also serves as an efficient buffer to release the inner stress and stop the falling of the active material. Thus, high reversible discharge/charge capacity of 1132/1123 mAh g−1 can be obtained after 100 cycles at current density of 100 mA g−1. The rate capability is also improved. In addition, Ni(OH) 2 /graphene exhibits excellent cycle stability at high current density. Discharge/charge capacities of 702/691 and 592/587 mAh g−1 are obtained at 1.0 and 2.0 A g−1 after 200 cycles at room temperature. It distinctly reveals that such special sheet-stacking hydroxide/graphene compound obtained through stirring solvothermal reaction with enhanced cycle performance and rate capability will be a promising anode material for lithium ion battery. Highlights • Sheet-stacking Ni(OH) 2 /graphene is get via stirring solvothermal method. • β-Ni(OH) 2 /GO sheet is obtained with large surface area and pore volume. • Reversible capacity of 1132 mAh g−1 are obtained after 100 cycles at 0.1 A g−1. • Ni(OH) 2 /GO delivers 702 mAh g−1 at 1.0 A g−1 after 200 cycles. [ABSTRACT FROM AUTHOR]

Abstract Phosphorus-based LIBs anode have attracted much attention for its high theoretical capacity. Much work so far has focused on the anode such as commercial red phosphorus and black phosphorus. However, little is known about the other phases of phosphorus. Here, we proposed a promising LIBs anode based on fibrous phosphorus and Hittorf's phosphorus. An Iodine-assisted CVD method was used to synthesize urchin-like fibrous phosphorus crystals and flower-like Hittorf's phosphorus crystals and the morphology of the twin phases was investigated systematically. Hittorf's Phosphorus exhibited an initial capacity of 2113.8 mA h g−1 and a capacity of 558.0 mA h g−1 after 40 cycles, whereas the fibrous phosphorus delivered a slightly lower initial discharge capacity of 1783.0 mA h g−1 but a higher capacity of 817.0 mA h g−1 after 40 cycles. It is concluded that fibrous phosphorus exhibited a best performance comparing with other single phases such as commercial red phosphorus (irreversible) and black phosphorus (the capacity fades from 1800.0 mA h g−1 to 200.0 mA h g−1 after 30 cycles). The Li-ion storage mechanism of fibrous phosphorus was investigated deeply. The uniform rod-like morphology and high conductivity of fibrous phosphorus improved the performance. Besides, the presence of Li 3 P and LiP phases contributed to the cyclability. [ABSTRACT FROM AUTHOR]

Abstract Wide application of high capacity anode materials for Li ion batteries (LIBs) is hindered by their structural instability. Assembling graphene and high capacity nanostructures with tight interaction is highly desirable for obtaining high performance anode materials. Here, we report a novel hydrothermal synthesis of homogeneous graphene-wrapped MnO nanowires. MnCO 3 anchors formed by the redox reaction between graphene oxide (GO) and MnOOH have helped to assemble the core-shell structured nanowires. With an optimized graphene amount, the graphene-wrapped MnO nanowires exhibit high reversible capacities at a low voltage platform ∼1 V (1185 mAh g−1 at 50 mA g−1), excellent rate performance (884 mAh g−1 at 500 mA g−1 and 508 mAh g−1 at 3 A g−1), high initial coulombic efficiency (86.3%), and long-term cyclic stability (undiminished after 500 cycles at 1 A g−1). These remarkable electrochemical performances in LIBs are significantly associated with the special core-shell conductive framework. Our results show that the highly reactive groups in GO can be used to in-situ assemble graphene-coated nanostructures, and that the MnO-graphene core-shell nanowires are promising anode candidate for LIBs. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

Highlights • A new hexagonal prisms CoO was assembled on reduced graphene oxide. • CoO in the composite is pure purity. • The composite performed high capacity as anode materials of lithium ion batteries. Abstract In this research, we use a modified sol-gel method to obtain a pure phase new hexagonal CoO on reduced graphene oxide by leading of polar solvent. In the electrochemical test, the CoO/rGO composite shows a remarkable performance of capacity as an anode of a lithium ion battery. The electrochemistry performance shows that the capacity of the composite can remain at 1300 mAh/g in 100 cycles without damping. The pure phase of CoO and its hexagonal morphology have been characterized by XRD, SEM and TEM. [ABSTRACT FROM AUTHOR]

Abstract Li 4 Ti 5 O 12 as the well-known "zero strain" anode material for lithium ion batteries (LIBs) suffers from low intrinsic ionic and electronic conductivity. The strategy of lattice doping has been widely taken to relieve the intrinsic issues. But the roles of the dopants are poorly understood. Herein, we propose to modulate the crystal structure and improve the electrochemical performance of Li 4 Ti 5 O 12 by substituting Li and Ti with Ca and Sm, respectively. The roles of Ca and Sm on the crystal structure and electrochemical performances have been comprehensively investigated by means of X-ray diffraction (XRD), neutron diffraction (ND) and electrochemical analysis. The Rietveld refinement of ND data indicate that Ca and Sm prefer to take 8a site (tetrahedral site) and 16d site (octahedral site), respectively. Li 3.98 Ca 0.02 Ti 4.98 Sm 0.02 O 12 has the longer Li1-O bond and shorter Ti-O bond length which reduces Li+ migration barrier as well as enhances the structure stability. Ca-Sm co-doping also alleviates the electrode polarization and enhances the reversibility of oxidation and reduction. In compared to bare Li 4 Ti 5 O 12 and Li 3.95 Ca 0.05 Ti 4.95 Sm 0.05 O 12 , Li 3.98 Ca 0.02 Ti 4.98 Sm 0.02 O 12 electrode shows the lower charge transfer resistance, higher Li+ diffusion coefficient, better rate capability and cycling performance. The proposed insights on the roles of dopants are also instructive to design high performance electrode materials by lattice doping. Graphical abstract Image Highlights • Ca and Sm prefer to take 8a site and 16d site, respectively. • Ca-Sm co-doping expand Li1-O bond and shorten Ti-O bond length. • Ca-Sm co-doping alleviates the electrode polarization. • Li 3.98 Ca 0.02 Ti 4.98 Sm 0.02 O 12 shows lower charge transfer resistance and higher Li+ diffusion coefficient. • Li 3.98 Ca 0.02 Ti 4.98 Sm 0.02 O 12 has better rate capability and cycling performance. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • MnO-carbon hybrid nano-fibers are fabricated via an electrospinning method. • Sintering temperature has an important influence on the performance of the obtained composites. • Material synthesized under optimum temperature can exhibit ideal fiber appearance with MnO particles embedded into it. • Formation mechanism of the materials are also analyzed. Abstract In this paper, MnO-carbon hybrid nanofibers are fabricated via an electrospinning method, while polyvinyl alcohol (PVA) and manganese acetylacetonate are used as raw materials. Composition, phase structure, and morphology of the products obtained under different sintering temperatures are studied with modern analytical instruments, and the electrochemical properties of the MnO/C fibers used as the lithium ion battery anode are also studied by continuous charge/discharge procedures. The results demonstrate that sintering temperature has an important influence on the performance of the obtained composites, and there is an optimum value for synthesizing MnO/C composites. Material synthesized under 600 °C can exhibit an ideal fiber appearance with MnO particles embedded into the material and deliver the highest capacity among all samples. The formation mechanism of the materials is also analyzed in detail in this paper. [ABSTRACT FROM AUTHOR]

Though molybdenum dioxide (MoO2) has attractive properties, conductivity is still threat to its implementation as it is very low compared to graphite. Herein, we have come up with MoO2‐rGO nanocomposite to mitigate this drawback, where nano sized MoO2 particles have been synthesised and supported with graphene sheets. Several physicochemical characterization techniques have been used to confirm the desired state of the obtained material. In this report, rGO supported MoO2 nanoparticles have been investigated as an anode for lithium ion battery and its electrochemical properties have been extensively studied. The new architecture exhibits excellent electrochemical performance by delivering a high discharge capacity of 1205 mA h g−1 even after 100 cycles. It also exhibits good rate capability by delivering discharge capacities of 809, 753, 675 mA h g−1 at current rates of 1 C, 3 C and 5 C, respectively. Simple inert annealing method was adopted to synthesize MoO2 NPs. The obtained MoO2 are composited with rGO by hydrothermal treatment. In the present work, MoO2‐rGO nanocomposite was probed as anode for lithium ion batteries. The electrochemistry of MoO2 is scrutinized by comparative study between MoO2 NPs, MoO2‐rGO nanocomposite and commercial MoO2. MoO2‐rGO delivered a enhanced discharge capacity of 1205 mA h g−1 and excellent stability over 100 cycles at current rate of 0.1 C. [ABSTRACT FROM AUTHOR]

Architecture of electrode materials plays an important role in achieving favorable electrochemical performance via providing fast electronic transport pathway and shorten lithium ion diffusion distance. Herein, ultrafine CoP nanoparticles were successfully embedded in carbon nanorod, which were grown on the biomass-derived carbon (BC). When applied as anode materials for lithium-ion batteries, these CoP@C/BC displayed capable specific capacity, remarkable rate ability and outstanding long-term cycling performance. The capacity was governed by combination of diffusion-controlled and capacitive processes, according to quantitative kinetic analysis. The good electrochemical performance is attributed to hierarchical construction of nanosized CoP embedded in carbon nanorod and BC with high conductivity composite, which relieve the volume changing of CoP and provide large electrode/electrolyte interface. The present design of hierarchical architecture can be extended to other transition metal-based oxides, sulfide and phosphide electrode materials for high performance alkali metal ion batteries. [ABSTRACT FROM AUTHOR]

Abstract Nanocomposites containing high capacity anode materials (such as Si, Sn or transition metal oxides) and carbon matrix, are widely studied to obtain high performance anodes for Li ion batteries (LIBs). However, these nanocomposites often suffer from low structural stability and high irreversible Li storage. Here, MnO-encapsulated graphene cubes are produced by calcination of homogeneous MnCO 3 -C composite cubes. The cubic graphene shells provide high conductivity and excellent structural stability to the MnO cores, and the high calcination temperature of 1200 °C can significantly reduce the specific surface area of the MnO@graphene cubes and thus reduce their irreversible capacity. The MnO@graphene cubes exhibit high Li storage capacity (1092 mAh g−1 at 50 mA g−1 and 790 mAh g−1 at 500 mA g−1) at a voltage platform ∼ 1 V, superior rate capability (586 mAh g−1 at 1000 mA g−1) and excellent long term cycling performance (undiminished after 500 cycles). Our results provide a useful method to design high performance graphene-based anode composites for LIBs. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

To improve the lithium storage capacity, electrochemical kinetics and stability of TiO 2 nanostructured electrode, a hybrid electrode of TiO 2 nanotubes coated with nitrogen-doped carbon (TiO 2 @NC) was rationally designed and prepared. With the unique coaxial nanotube structure, the porous TiO 2 nanotubes would offer short paths for Li + diffusion and numerous active sites, while the N-doped carbon matrix would prefer fast charge transportation and buffer the volume change of TiO 2 during lithiation/delithiation processes. In particular, a high reversible specific capacity of 480 mA h g −1 at a current density of 100 mA g −1 was achieved when evaluated as anodes for lithium ion batteries. The high capacity, outstanding cycling stability, and remarkable rate performance may attributed to its unique morphology and the synergetic effect of porous TiO 2 nanotube and conductive N-doped carbon nanoshell on the basis of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). [ABSTRACT FROM AUTHOR]

We present a uniform rhombohedral Ni@ZnO bimetallic oxide host over carbon nanofibers (CNF) as an anode material for Li-ion batteries. Ni@ZnO was produced by annealing a Ni@zeolitic imidazolate framework (ZIF-8) hierarchically decorated over CNFs. The rationally-designed freestanding composite exhibited promising stability in electrochemical performance. A first reversible capacity of 1051 mA·h·g −1 was measured at a current density of 100 mA·g −1 , and 88% of this capacity was retained after 100 cycles. We attribute this high capacity retention to the hierarchical structure of the Ni@ZnO-enwrapped carbon framework encapsulating the conductive CNFs, as demonstrated by scanning and transmission electron microscopy. The composite electrode also showed a high specific capacity of ∼497 mA·h·g −1 in high-rate testing at 1000 mA·g −1 , because the cage-like framework of the material allowed rapid charge transfer and Li-ion diffusion in the anode. [ABSTRACT FROM AUTHOR]

Abstract Iron oxide, a promising anode material for lithium ion batteries, has a high theoretical specific capacity but exhibits poor cycling performance and rate capability. To resolve these issues, 150 nm sized carbon coated, hollow Fe 3 O 4 nanoellipsoids are designed in this study. Owing to the relatively high utilization ratio of Fe 3 O 4 and the buffer provided by the carbon layer, this composite has enhanced lithium ion storage properties and long cycle life. From half-cell measurements, the capacity is found to be in excess of 400 mAh g−1 even after 1000 cycles at 5 A g−1. And then, a facile and practical strategy is used to gain a relatively high compressed density (∼1.87 g cm−3), so the volumetric capacity of the Fe 3 O 4 @C electrode can be further enhanced by subjecting it to compression. In the full cell test, the Fe 3 O 4 @C electrode has a specific capacity of 400 mAh g−1 and volumetric capacity of 749 mAh cm−3 after 100 cycles. The improvement in cycling stability can be attributed to minimal volume expansion and the stability of the solid-electrolyte interphase (SEI) layer, over the nanoparticles. Finally, the evolution of solid-electrolyte interphase layer is indirectly monitored and the progressive loss of active lithium is quantitatively measured. Graphical abstract Image 1 Highlights • A facile and template-free method is used to obtain Fe 3 O 4 @C nanoellipsoids. • The as-prepared nano-composite shows an admirable compressed density of 1.87 g cm−3. • The designed anode shows superior Li+ storage properties in half and full cell. • CI and CIC are plotted in the figure to evaluate stability the SEI film. [ABSTRACT FROM AUTHOR]

In this paper, novel three dimensional hierarchical porous Sn-Ni (3D-HP Sn-Ni) alloys were investigated as a promising anode for high-performance Li ion batteries (LIBs), which was fabricated by pulse electrodeposition of mesoporous Sn-Ni alloy made of ultrafine nanoparticles on the 3D nanoporous copper substrate from chemical dealloying of as-cast Al 55 Cu 45 (at.%) alloy slices in the HCl solution. The results show that the as-obtained 3D-HP Sn-Ni alloys are typically characteristic of open, bicontinuous, interpenetrating bimodal pore size distribution comprising large-sized (hundreds of nm) ligament-channel network architecture with highly porous channel walls (several nm). Compared to the two dimensional nanoporous Sn-Ni (2D-NP Sn-Ni) thin films, the 3D-HP Sn-Ni alloys as anode for LIBs show superior cycling stability with reversible specific capacity of 0.25 mAh cm −2 and coulombic efficiency of more than 95% up to 200 cycles. Moreover, the reversible capacity as high as 0.22 mAh cm −2 can be achieved even after a series of high-rate charge–discharge cyclings. The satisfactory electrochemical properties can be mainly ascribed to the unique 3D hierarchical porous structure, large contact surface area between active material and electrolyte, as well as good buffer effect of inactive component, which is greatly beneficial to alleviate the huge volume variation, enhance the loading mass of active material, shorten the Li + migration distance and improve the electron conductivity. We believe that this present work can provide a promising anode candidate towards practical application of high-performance LIBs. [ABSTRACT FROM AUTHOR]

Abstract Lithium-ion batteries (LIBs) with SiO x anodes possess high energy density, stemming from the Li-Si alloying reaction. However, several issues hinder the application of SiO x anodes in commercialized LIBs. In particular, the low electronic conductivity and sluggish kinetics of SiO x result in inadequate electrochemical performance. Herein, we report the use of a selective alcoholysis-based reaction to prepare a (C-Ti x Si 1 -x O y)@C composite using SiCl 4 , TiCl 4 , and ethylene glycol (EG) with benzene. The preferential reaction between EG and TiCl 4 results in Ti3+ doping as well as the formation of a homogenous distribution of Ti ions. During the selective alcoholysis reaction, the Ti-Si-O-C-H sol transforms into a (C-Ti x Si 1 -x O y)@C composite and benzene decomposes into conductive carbon matrices through dispersion forces. The combination of Ti doping and carbon coating greatly enhance the conductivity of SiO x ; in addition, the incorporated carbon acts as an effective oxide buffer, preventing structural degradation. Thus, the (C-Ti x Si 1 -x O y)@C composite exhibits a high Li-ion diffusion coefficient and low charge-transfer resistance, resulting in excellent capacity retention of 88.9% over 600 cycles at a high current density of 1 A g−1 with a high coulombic efficiency of ∼99%. Graphical abstract Image 1 Highlights • The (C-Ti x Si 1 -x O y)@C was synthesized by a selective alcoholysis-based reaction. • The combination of Ti doping and carbon coating enhance the conductivity of SiO x. • Carbon coating acts as an effective oxide buffer, preventing structural degradation. • The (C-Ti x Si 1 -x O y)@C achieve superior cyclability and rate capability. [ABSTRACT FROM AUTHOR]

Abstract Mesoporous Ta 2 O 5 nanoparticles (NPs) with high surface area were prepared using an 1-methyl 3-(2 - bromoethyl) imidazolium bromide ionic liquid (IL) as structure directing and porous inducing agent. We have characterized the Ta 2 O 5 nanoparticles (NPs) by XRD, BET analysis, TEM, SEM, DRS, FTIR, Raman spectroscopy and TG-DTA. From BET analysis a large surface area of asprepared Ta 2 O 5 NPs was found to be 236.1 m2 g−1. More importantly, Ta 2 O 5 nanoparticles are less explored anode material for lithium ion battery as well as an effective photocatalyst for hydrogen generation. The significant reversible capacity of 150 mAh g−1 has been observed in Ta 2 O 5 NPs even after 50 cycles at C/10 current rate. In addition to this, asprepared Ta 2 O 5 NPs synthesized using IL exhibited remarkable hydrogen generation of 563.5 μmolg−1 h−1 compared to other Ta 2 O 5 samples which are due to high surface area, small pore wall thickness and presence of surface hydroxyl groups on the photocatalyst. Graphical abstract Mesoporous Ta 2 O 5 NPs are employed as anode materials for lithium ion battery and efficient photocatalyst for photocatalytic hydrogen generation. Image 1 Highlights • Mesoporous Ta 2 O 5 NPs have been prepared by using ionic liquid as co-solvent. • Ta 2 O 5 NPs delivered charge capacity of 150 mAh g−1 after 50 cycles at C/10 current rate. • Ta 2 O 5 NPs exhibited significant H 2 generation of 563.5 μmolg−1 h−1. [ABSTRACT FROM AUTHOR]

Novel 1-D tube-in-tube structured NiO nanobelts were prepared by electrospinning process and subsequent one-step thermal treatment process. Nanobelt structured 1-D composite was electrospun from an aqueous solution containing poly(vinylpyrrolidone), citric acid, and dextrin which synergistically contributed to morphology control. The chemicals that optimized surface tension and viscosity of the aqueous solution enabled stable electrospinning process. Especially, dextrin played an important role in stable nanobelt formation due to its hygroscopic nature. During one-step oxidation process, the polymer composited nanobelt turned into carbon-free NiO@void@NiO tube-in-tube structured nanobelt by repeated combustion and contraction processes and Ostwald ripening mechanism. NiO tube-in-tube nanobelt prepared at 400 °C showed superior lithium-ion storage performances compared to those of NiO-C nanobelt and porous NiO nanobelt obtained at 300 and 500 °C, respectively. The discharge capacity of the tube-in-tube structured nanobelts after the 200th cycle at a current density of 1.0 A g −1 was 992 mA h g −1 . Also, high discharge capacity of 531 mA h g −1 at a current density of 10.0 A g −1 proved its excellent power density. High structural stability and morphological benefits of tube-in-tube nanobelts resulted in superior lithium storage performance. [ABSTRACT FROM AUTHOR]

Porous CoP 3 @PPy microcubes are synthesized from the cubic Co 3 [Co(CN) 6 ] 2 precursors followed by PPy coating. When used as anode material for lithium ion batteries, a large specific capacity of 1310 mAh g −1 can be obtained for CoP 3 @PPy composite at 100 mA g −1 , and retains 650 mAh g −1 after 220 cycles at 500 mA g −1 . Even at high current density of 4000 mA g −1 , the CoP 3 @PPy composite still maintains a reversible capacity as high as 800 mAh g −1 . When matched with LiFePO 4 for full battery, a high capacity of 540 mAh g −1 can be obtained at 100 mA g −1 after 100 cycles. The improved lithium storage performance of CoP 3 @PPy is ascribed to the unique porous structure of CoP 3 microcubes and the homogeneous PPy buffer/conducting layers, which can alleviate the giant volume changes and facilitate fast charge transfer during the lithiation/delithiation process. [ABSTRACT FROM AUTHOR]

Graphene like graphite (GLG) samples containing various amounts of oxygen are prepared from the thermal reduction of graphite oxide (GO) and are used as anodes of lithium ion battery. The oxygen/carbon (O/C) ratios in GLG varied from 0 to 0.08, depending on the thermal reduction temperature, oxygen gas pressure during heat treatment and degree of oxidation of the starting GO. The cell voltage during discharge almost linearly increases below 1 V independent of the oxygen contents in them. The discharge capacity of GLG above 1 V increases with the increase in the oxygen content with a slope of lithium/oxygen ratio of 3 at lower O/C ratios. Then the slope becomes smaller and the discharge capacity reaches 673 mAhg −1 for GLG with O/C = 0.08. When GLG is treated with hydrogen gas, considerable amounts of oxygen atoms are substituted by hydrogen ones. The discharge capacity of the resulting GLG samples is larger than that expected form their oxygen contents and coulombic efficiency is slightly improved up to 59%. Introduction of oxygen atoms within carbon layers results in the large increase in the interlayer spacing during charging, which leads to accommodation of large amounts of lithium ions. [ABSTRACT FROM AUTHOR]

Waste antibiotics into the natural environment are the large challenges to the environmental protection and the human health, and the unreasonable disposal of the expired antibiotics is a major pollution source. Herein, to achieve the innocent treatment and the resource recovery, the expired tetracycline was tried to be reutilized as the electrode active material in lithium ion battery (LIB) for the first time. The micro-structure and element component of the expired tetracycline were characterized by scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Furthermore, the corresponding electrochemical performances were also investigated by galvanostatic charge/discharge and cyclic voltammetry (CV). To be satisfactory, the expired-tetracycline-based electrode delivered the initial specific discharge capacity of 371.6 mAh/g and the reversible specific capacity of 304.1 mAh/g after 200 cycles. The decent results will not only offer an effective strategy to recycle the expired tetracycline, but also shed a new light on the cyclic economy and the sustainable development. [ABSTRACT FROM AUTHOR]

High energy demand has directed the present‐day research towards synthesis and applications of heterostructured nanomaterials such as molybdenum oxysalts over mono‐structured nanomaterials. Molybdenum oxysalt is a promising anode material for lithium ion batteries because of its high theoretical lithium storage capacity (998 mAh g−1) and flexible composition. Engineering the morphology and porosity of a material has proven to be a productive approach towards enhancing its performances. Here in, we have demonstrated a one pot synthesis of mesoporous MnMoO4 nanorods and its enhanced electrochemical performance for Li‐ion battery anode. Several physiochemical techniques have been used to validate the desired properties and purity of the synthesized material. It exhibits high lithiation capacity of 1050 mAh g−1 and stability over 100 cycles at 0.5 C. The enhanced performance is attributed to its structural stability and mesoporous nature. [ABSTRACT FROM AUTHOR]

• TiO 2 nanoflowers percolated with carbon nanotubes (CNTs) are designed by solution method. • CNTs improve the electronic conductivity of TiO 2 nanoflowers. • The optimized TiO 2 @CNTs hybrids exhibit excellent cycle performance for lithium storage. Titanium dioxide (TiO 2) is a promising anode materials for lithium-ion batteries due to its advantages such as good safety, reliability, reversible capacity, high content and environmental friendliness. However, its inherent defects such as low ion diffusion coefficient and poor electrical conductivity seriously limit its practical application. In this study, we designed a unique hybrid structure of TiO 2 nanoflowers percolated with carbon nanotubes (CNTs) by a low cost solution method. The hierarchical structure of TiO 2 increases the specific surface area and shortens the ion/electron transport distance. CNTs are uniformly embedded in the interior of TiO 2 nanoflowers to improve the overall conductivity and flexibility. As a result, the optimized TiO 2 @CNTs as lithium ion battery (LIBs) anode, showed excellent long-term cycle performance (177.5 mA h g−1, at 1.0 A g−1 after 600 cycles). The excellent reversibility and electrochemical kinetic performance are also studied by CV and EIS measurements. This work provides a new perspective for exploring efficient lithium storage for high performance anode materials. [ABSTRACT FROM AUTHOR]