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A hybrid gel–solid-state polymer electrolyte has been used as the separator and an electrolyte for lithium oxygen batteries. It can not only avoid electrolyte evaporation but also protect the lithium metal anode during reactions over long-term cycling. Due to its high ionic conductivity and low activation energy, excellent cycling performance is demonstrated, in which the terminal voltage is higher than 2.2 V after 140 cycles at 0.4 mA cm−2, with a capacity of 1000 mA h g(composite)−1. [ABSTRACT FROM AUTHOR]

A novel and low-cost FeP anode with a high capacity of 764.7 mA h g−1 synthesized by a ball-milling method is reported for sodium ion batteries. Ex situ X-ray diffraction and transmission electron microscopy have been used to explore the sodium storage mechanism of FeP. [ABSTRACT FROM AUTHOR]

Highly oriented LiFePO 4 thin-film electrodes were fabricated via chemical solution deposition combined with spin coating. The effects of the precursor concentrations and types of substrates on microstructures and electrochemical performances were studied. Single-phase LiFePO 4 with orientations perpendicular to the (211)/(020) and (311) planes prepared using stainless steel as substrate presents the capacity of 4.9 μAh·cm − 2 and the apparent activation energy of 59.2 kJ·mol − 1 , indicating its great potential to be used as cathode material for lithium thin film batteries. [ABSTRACT FROM AUTHOR]

A series of Li 2 Fe 1-3 x /2 V x P 2 O 7 ( x = 0, 0.025, 0.05, 0.075, and 0.1) cathode materials for LIBs were prepared by the sol-gel method. Structural characterization of Li 2 Fe 1-3 x /2 V x P 2 O 7 ( x = 0, 0.025, 0.05, 0.075, and 0.1) samples was conducted by synchrotron X-ray diffraction. The morphology and oxidation states of Fe 2+ and V 3+ in the Li 2 Fe 1-3 x /2 V x P 2 O 7 samples were confirmed by scanning electron microscopy and magnetic susceptibility measurements, respectively. The electrochemical measurements indicated that Li 2 Fe 1-3 x /2 V x P 2 O 7 ( x = 0.025) delivered the higher reversible capacity of 79.9 mAh g −1 at 1 C in the voltage range of 2.0 - 4.5 V with higher 77.9% capacity retention after 300 cycles than those of Li 2 FeP 2 O 7 (48.9 mAh g −1 and 72.6%). Moreover, the rate capability of Li 2 Fe 1-3 x /2 V x P 2 O 7 ( x = 0.025) were also significantly enhanced through vanadium substitution to iron of Li 2 Fe 1-3 x /2 V x P 2 O 7 . The vanadium substituted to Fe2 site of Li 2 FeP 2 O 7 decreases Li occupying the Li5 position in the FeO 5 unit, leading to a low degree exchange between Li and Fe in the MO 5 (M = Li and Fe). The low degree cation disorder was beneficial to lithium-ion extraction/insertion during the charge-discharge process and hence enhances the capacity and rate capability. [ABSTRACT FROM AUTHOR]

Sodium-ion energy storage, including sodium-ion batteries (NIBs) and electrochemical capacitive storage (NICs), is considered as a promising alternative to lithium-ion energy storage. It is an intriguing prospect, especially for large-scale applications, owing to its low cost and abundance. MoS2 sodiation/desodiation with Na ions is based on the conversion reaction, which is not only able to deliver higher capacity than the intercalation reaction, but can also be applied in capacitive storage owing to its typically sloping charge/discharge curves. Here, NIBs and NICs based on a graphene composite (MoS2/G) were constructed. The enlarged d-spacing, a contribution of the graphene matrix, and the unique properties of the MoS2/G substantially optimize Na storage behavior, by accommodating large volume changes and facilitating fast ion diffusion. MoS2/G exhibits a stable capacity of approximately 350 mAh g−1 over 200 cycles at 0.25 C in half cells, and delivers a capacitance of 50 F g−1 over 2000 cycles at 1.5 C in pseudocapacitors with a wide voltage window of 0.1-2.5 V. [ABSTRACT FROM AUTHOR]

Abstract: A high performance Li3V2(PO4)3 cathode material for lithium ion batteries was synthesized by the microwave-assisted hydrothermal method followed by a post annealing process. The synchrotron X-ray diffraction analysis results confirmed that single-phase Li3V2(PO4)3 with monoclinic structure was obtained. Scanning electron microscope and transmission electron microscope images revealed that the as-prepared Li3V2(PO4)3 was composed of nanowires and microsized particles. Electrochemical results demonstrated that the Li3V2(PO4)3 electrode measured at 10 C after 500 cycles can deliver discharge capacities of 85.4 mAh g−1 and 103.4 mAh g−1, with a capacity retention of 99.3% and 95.9%, in the voltage ranges of 3.0–4.3 V and 3.0–4.8 V, respectively, indicating good cycling stability. Furthermore, the electrochemical performance of Li3V2(PO4)3 in ionic liquid electrolytes between 3.0 V and 4.8 V was also measured. [Copyright &y& Elsevier]

Abstract: To overcome the problems of vanadium dissolution and the higher charge transfer resistance that results from it, VO2/graphene composite has been synthesized by an in-situ hydrothermal process directly from graphene oxide and V2O5, and characterized by X-ray diffraction, Raman spectroscopy, FT-IR spectroscopy, thermogravimetric analysis, atomic force microscope, and field emission scanning electron microscopy. Electrochemical tests show that the VO2/graphene composite features high discharge capacity (380 mAh g−1) and 99% capacity retention after 50 cycles. It has very low resistance, only 67% of that of pure VO2, indicating the enhancement of electronic conductivity. Carbon dispersed in the electrode material can provide a pathway for electron transport, resulting in improvement of the electronic conductivity. Graphene woven VO2 nanoribbons prevent the agglomeration of VO2 nanoribbons, meanwhile graphene and the VO2 nanoribbons together form a porous network in the random hybrid composite that can be filled with electrolyte, resulting in superior performance and enhanced reversible capacity in comparison with the pure VO2. Thus, this work provides a facile route to synthesize VO2/graphene composite which shows excellent electrochemical performance and is a potential material for lithium ion battery. [Copyright &y& Elsevier]

Abstract: The lithium/sulfur battery is a promising electrochemical system with high capacity, which is well-known to undergo a complex multistep reaction during the discharge process. Two types of electrolytes including poly(ethylene glycol) dimethyl ether (PEGDME)-based and 1,3-dioxolane (DOL)/dimethoxyethane (DME)-based electrolytes were investigated here. Furthermore, LiNO3 additive was introduced into the electrolyte in order to effectively eliminate the overcharge effect. The lithium sulfur battery with 1.0 M LiN(CF3SO2)2 in PEGDME with 0.1 M LiNO3 shows highly stable reversible capacity of 624.8 mAh g−1 after 200 cycles and improved average coulombic efficiency of 98%. [Copyright &y& Elsevier]

Abstract: A hybrid electrolyte energy storage system combining the features of supercapacitors and lithium batteries has been constructed. It consists of MnO2 nanoflakes in 1M Li2SO4 aqueous electrolyte as the cathode and lithium foil in ionic liquid (1M lithium bis(trifluoromethanesulfonyl)imide (LiNTf2) in N-methyl-N-propyl pyrrolidinium bis(trifluoromethanesulfonyl)imide ([C3mpyr][NTf2])) electrolyte as the anode, separated by a lithium super ionic conductor glass ceramic film (LiSICON). This system shows the advantages of both a supercapacitor (long cycle life) and a lithium battery (high energy), as well as low cost and improved safety due to the combination of ionic liquid and ceramic solid state electrolyte in lithium side, which can reduce the formation and prevent the penetration of lithium dendrites. The specific energy for the cathode materials in the hybrid electrolyte system is 170Whkg−1 with more than 85% retention up to 2400cycles. This system is a great candidate for stationary batteries storing solar and wind energy. [Copyright &y& Elsevier]

Abstract: Sodium ion battery is a promising electrical energy storage system for sustainable energy storage applications due to the abundance of sodium resources and their low cost. In this communication, the electrochemical properties of sodium ion storage in reduced graphene oxide (RGO) were studied in an electrolyte consisting of 1M NaClO4 in propylene carbonate (PC). The experimental results show that the RGO anode allowed significant sodium ion insertion, leading to higher capacity at high current density compared to the previously reported results for carbon materials. This is due to the fact that RGO possesses higher electrical conductivity and is a more active host, with large interlayer distances and a disordered structure, enabling it to store a higher amount of Na ions. RGO anode exhibits high capacity combined with long-term cycling stability at high current densities, leading to reversible capacity as high as 174.3mAhg−1 at 0.2C (40mAg−1), and even 93.3mAhg−1 at 1C (200mAg−1) after 250 cycles. Furthermore, RGO could yield a high capacity of 141mAhg−1 at 0.2C (40mAg−1) over 1000 cycles. [Copyright &y& Elsevier]

ABSTRACT: From energy and environmental consideration, an industrial waste product, coal tar pitch (CTP), is used as the carbon source for Si/AC composite. We exploited a facile sintering method to largely scale up Si/amorphous carbon nanocomposite. The composites with 20wt.% silicon with PVdF binder exhibited stable lithium storage ability for prolonged cycling. The composite anode delivered a capacity of 400.3mAhg−1 with a high capacity retention of 71.3% after 1000 cycles. Various methods are used to investigate the reason for the outstanding cyclability. The results indicate that the silicon nanoparticles are wrapped by amorphous SiO x and AC in Si/AC composite. This uniform structure is very favorable to lithium storage, the SiO x and AC layers can supply sufficient conductivity and strong elasticity to suppress the stress resulting from the reaction of Si with Li during charge/discharge process. [Copyright &y& Elsevier]

Abstract: LiNi1/3Mn1/3Co1/3O2 (NMC) as a cathode material for lithium ion batteries has been synthesized by the sol–gel method. The X-ray diffraction Rietveld refinement results indicated that single-phase NMC with hexagonal layered structure was obtained. Scanning electron microscope images revealed well crystallized NMC with uniform particle size in the range of 100–200 nm. The performance of the NMC electrodes with sodium carboxylmethyl cellulose (CMC), poly(vinylidene fluoride) (PVDF), and alginate from brown algae as binders was compared. Constant current charge–discharge test results demonstrated that the NMC electrode using CMC as binder had the highest rate capability, followed by those using alginate and PVDF binders, respectively. Electrochemical impedance spectroscopy test results showed that the electrode using CMC as the binder had lower charge transfer resistance and lower apparent activation energy than the electrodes using alginate and PVDF as the binders. The apparent activation energies of NMC electrodes using CMC, alginate, and PVDF as binders were calculated to be 27.4 kJ mol−1, 33.7 kJ mol−1, and 36 kJ mol−1, respectively. [Copyright &y& Elsevier]

Abstract: A series of Li x CoPO4 (x =0.90, 0.95, 1, 1.05) compounds with different lithium content in the starting compositions were prepared by the sol–gel method. The phase identification was carried out by X-ray diffraction and neutron diffraction. The structure, atom positions, and occupancies were characterized by neutron diffraction. The morphology of Li x CoPO4 (x =0.90, 0.95, 1, 1.05) was examined by field emission scanning electron microscopy. Electrochemical analysis indicated that Li0.95CoPO4 presented the highest discharge capacity at various current densities among all the different x value compounds. The Li0.95CoPO4 showed better cycling stability and coulombic efficiency in the room temperature ionic liquid electrolyte ([C3mpyr][NTf2] containing 1M LiNTf2) at various current densities in the voltage range of 3.5–5.0V than in the conventional electrolyte (1M LiPF6 in ethylene carbonate:diethyl carbonate). [Copyright &y& Elsevier]

Three types of transition metal oxide/carbon composites including FeO/C, NiO/C and CuO/CuO/C synthesized via spray pyrolysis were used as anode for lithium ion battery application in conjunction with two types of ionic liquid: 1 M LiN(SOCF) (LiTFSI) in 1-ethyl-3-methyl-imidazolium bis(fluorosulfonlyl)imide (EMI-FSI) or 1-methyl-1-propylpyrrolidinium bis(fluorosulfonyl)imide (Py13-FSI). From the electrochemical measurements, the composite electrodes using Py13-FSI as electrolyte show much better electrochemical performance than those using EMI-FSI as electrolyte in terms of reversibility. The FeO/C composite shows the highest specific capacity and the best capacity retention (425 mAh g) under a current density of 50 mA g for up to 50 cycles, as compared with the NiO/C and CuO/CuO/C composites. The present research demonstrates that Py13-FSI could be used as an electrolyte for transition metal oxides in lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Abstract: Si/graphene composite was prepared by simply mixing of commercially available nanosize Si and graphene. Electrochemical tests show that the Si/graphene composite maintains a capacity of 1168mAhg−1 and an average coulombic efficiency of 93% up to 30 cycles. EIS indicates that the Si/graphene composite electrode has less than 50% of the charge-transfer resistance compared with nanosize Si electrode, evidencing the enhanced ionic conductivity of Si/graphene composite. The enhanced cycling stability is attributed to the fact that the Si/graphene composite can accommodate large volume charge of Si and maintain good electronic contact. [Copyright &y& Elsevier]

Abstract: NiO–C nanocomposite was prepared by a spray pyrolysis method using a mixture of Ni(NO3)2 and citric acid solution at 600°C. The microstructure and morphology of the NiO–C composite were characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) mapping, and thermogravimetric analysis (TGA). The results showed that the NiO nanoparticles were surrounded by amorphous carbon. Electrochemical tests demonstrated that the NiO–C nanocomposites exhibited better capacity retention (382mAhg−1 for 50cycles) than that of pure NiO (141mAhg−1 for 50cycles), which was also prepared by spray pyrolysis using only Ni(NO3)2 as precursor. The enhanced capacity retention can be mainly attributed to the NiO–C composite structure, composed of NiO nanoparticles surrounded by carbon, which can accommodate the volume changes during charge–discharge and improve the electrical conductivity between the NiO nanoparticles. [Copyright &y& Elsevier]

Abstract: Carbon-coated SnO2 nanoparticles were prepared by a novel facile route using commercial SnO2 nanoparticles treated with concentrated sulfuric acid in the presence of sucrose at room temperature and ambient pressure. The key features of this method are the simple procedure, low energy consumption, and inexpensive and non-toxic source materials. As-prepared core/shell nanoparticles were characterized by X-ray powder diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDX), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). The electrochemical measurements showed that the carbon-coated SnO2 nanoparticles with 10% carbon and using carboxymethyl cellulose (CMC) as a binder displayed the best electrochemical performance with the highest specific capacity of 502mAhg−1 after 50 cycles at a current density of 100mAg−1. In addition, owing to the water solvability of CMC, the usage of CMC as binder makes the whole electrode fabrication process cheaper and more environmental friendly. [Copyright &y& Elsevier]

Abstract: SnO2 meso-scale tubes were synthesized by anodic electrochemical deposition under ambient conditions. Controlled self-bubbling O2 acted as both the template and the oxidizing agent for obtaining SnO2 tube structures at the interface of the gas (O2) and the liquid (electrolyte). Electrochemical testing showed that the meso-scale tubes have higher discharge capacity and better rate capability than the “microbowls” produced by varying the deposition conditions. From the Arrhenius plot, the apparent activation energies were calculated to be 58.4 and 90.1kJmol−1 for the meso-scale tubes and the microbowls, respectively, indicating that the meso-scale structure allows shorter diffusion routes for the lithium ions or for easier interaction with lithium. [Copyright &y& Elsevier]

Abstract: Nickel sulfides, pure Ni3S2 and a mixture of Ni7S6–NiS, were synthesized through a solvothermal process. The nickel sulfide powders were characterized by X-ray diffraction, scanning electron microscopy, and electrochemical testing. The results showed that the capacity of NiS–Ni7S6 is much higher than that of Ni3S2, when used as the cathode in a lithium cell with an organic solvent-based electrolyte, l M lithium bis(trifluoromethanesulfonyl)amide (LiNTf2) in poly(ethylene glycol) dimethyl ether 500. The NiS–Ni7S6 electrodes were also tested with an ionic liquid electrolyte consisting of 1 M LiNTf2 in N-methyl-N-propyl pyrrolidinium bis(trifluoromethanesulfonyl)amide ([C3mpyr][NTf2]) to compare with organic-solvent based electrolytes. The results revealed that the ionic liquid is a useful solvent for use with this cathode material. [Copyright &y& Elsevier]

Abstract: Highly flexible, paper-like, free-standing polypyrrole and polypyrrole–LiFePO4 composite films were prepared using the electropolymerization method. The films are soft, lightweight, mechanically robust and highly electrically conductivity. The electrochemical behavior of the free-standing films was examined against lithium counter electrode. The electrochemical performance of the free-standing pure PPy electrode was improved by incorporating the most promising cathode material, LiFePO4, into the PPy films. The cell with PPy–LiFePO4 composite film had a higher discharge capacity beyond 50 cycles (80mAh/g) than that of the cell with pure PPy (60mAh/g). The free-standing films can be used as electrode materials to satisfy the new market demand for flexible and bendable batteries that are suitable for the various types of design and power needs of soft portable electronic equipment. [Copyright &y& Elsevier]

Abstract: MnO2 nanowires were electrodeposited onto carbon nanotube (CNT) paper by a cyclic voltammetric technique. The as-prepared MnO2 nanowire/CNT composite paper (MNCCP) can be used as a flexible electrode for electrochemical supercapacitors. Electrochemical measurements showed that the MNCCP electrode displayed specific capacitances as high as 167.5F g−1 at a current density of 77mA g−1. After 3000 cycles, the composite paper can retain more than 88% of initial capacitance, showing good cyclability. The CNT paper in the composite acted as a good conductive and active substrate for flexible electrodes in supercapacitors, and the nanowire structure of the MnO2 could facilitate the contact of the electrolyte with the active materials, and thus increase the capacitance. [Copyright &y& Elsevier]

Abstract: Porous Co3O4 nanostructured thin films are electrodeposited by controlling the concentration of Co(NO3)2 aqueous solution on nickel sheets, and then sintered at 300°C for 3h. The as-prepared thin films are characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The electrochemical measurements show that the highly porous Co3O4 thin film with the highest electrochemically active specific surface area (68.64m2 g−1) yields the best electrochemical performance compared with another, less-porous film and with a non-porous film. The highest specific capacity (513mAhg−1 after 50 cycles) is obtained from the thinnest film with Co3O4 loaded at rate of 0.05mgcm−2. The present research demonstrates that electrode morphology is one of the crucial factors that affect the electrochemical properties of electrodes. [Copyright &y& Elsevier]

Solid‐state lithium–air batteries (SSLABs) have become the focus of next‐generation advanced batteries due to their safety and high energy densities. Current research on SSLABs is mainly centered on solid‐state electrolytes (SSEs). Although SSEs exhibit excellent properties, such as good stability, high safety, and great mechanical strength, they also display several distinct weaknesses of low ionic conductivities, poor stabilities in air, and high interfacial impedances, which will require sustained attentions for further investigations. This review first overviews the development history of SSEs achieved in terms of Li–air batteries. Subsequently, the fundamental properties, preparation methods, merits and drawbacks of different SSEs, along with their use in SSLABs, and the optimization strategy, especially for the inorganic solid electrolytes, polymer electrolytes, and hybrid electrolytes are comprehensively summarized. Finally, the research progresses made with SSEs are outlined, and critical insights and approaches for the remaining challenges of electrolytes and commercial application of SSLABs are proposed, which include advanced characterization, combining experiments and artificial intelligence such as theoretical calculations, and constructing selective permeability membranes. It is expected that this timely review will provide researchers with an integrated, systematic, and in‐depth understanding of SSEs and guidelines for future research, thus further promoting the commercial application of SSLABs. [ABSTRACT FROM AUTHOR]

Abstract: Highly flexible and bendable free-standing polypyrrole (PPy) films were prepared using the electrochemical polymerization method. The paper-like films are soft, lightweight, mechanically robust, and highly electrically conductive. The morphologies and electrochemical behaviour of the free-standing pure PPy films were affected by the electrochemical polymerization conditions. The free-standing films show promise as cathodes for flexible and bendable batteries. [Copyright &y& Elsevier]

Cobalt substitution for manganese sites in Na0.44MnO2 initiates a dynamic structural evolution process, yielding a composite cathode material comprising intergrown P2 and P3 phases. The novel P2/P3 composite cathode exhibits a reversible phase transition process during Na+ extraction/insertion, showcasing its attractive battery performance in sodium-ion batteries. [ABSTRACT FROM AUTHOR]

Hydrogen‐bonded organic frameworks (HOFs) are considered as potential choice for future energy storage systems due to their adjustable chemistry, environment friendliness, and cost‐effectiveness. In this study, structurally stabilized and aldehyde‐tuned hydrogen‐bonded organic frameworks (HOFs‐8) are designed and prepared to contain arrayed electronegative sites for sodium‐ion storage. Benefitting from the flexible hydrogen bond and unique structural symmetry, HOFs‐8 can achieve efficient utilization of the active sites and fast transport of sodium ions and electrons. The HOFs‐8 electrode exhibits an impressive lifespan of 5000 cycles at 3.66 A g−1 (20 C). In situ Fourier Transform infrared spectroscopy (in situ FT‐IR) and ex situ X‐ray Photoelectron Spectroscopy (ex situ XPS) analyses are performed to illustrate the mechanism of sodium‐ion storage involving aldehyde‐tuned C═O. Additionally, flexible hydrogen bonds in HOFs materials with unique structural symmetries are investigated to elucidate the mechanism of hydrogen bonding for improving their electrochemical properties. Density functional theory (DFT) simulations verified that HOFs‐8 has excellent Na+ diffusion kinetics, enabling it to demonstrate outstanding rate capability. This work offers insight into the design of new electrodes and improved HOFs, which are expected to have tremendous potential in energy storage systems. [ABSTRACT FROM AUTHOR]

Zn deposition with a surface‐preferred (002) crystal plane has attracted extensive attention due to its inhibited dendrite growth and side reactions. However, the nucleation and growth of the Zn(002) crystal plane are closely related to the interfacial properties. Herein, oriented growth of Zn(002) crystal plane is realized on Ag‐modified surface that is directly visualized by in situ atomic force microscopy. A solid solution HCP‐Zn (~1.10 at. % solubility of Ag, 30 °C) is formed on the Ag coated Zn foil (Zn@Ag) and possesses the same crystal structure as Zn to reduce its nucleation barrier caused by their lattice mismatch. It merits oriented Zn deposition and corrosion‐resistant surface, and presents long cycling stability in symmetric cells and full cells coupled with V2O5 cathode. This work provides insights into interfacial regulation of Zn anodes for high‐performance aqueous zinc metal batteries. [ABSTRACT FROM AUTHOR]

Zn deposition with a surface‐preferred (002) crystal plane has attracted extensive attention due to its inhibited dendrite growth and side reactions. However, the nucleation and growth of the Zn(002) crystal plane are closely related to the interfacial properties. Herein, oriented growth of Zn(002) crystal plane is realized on Ag‐modified surface that is directly visualized by in situ atomic force microscopy. A solid solution HCP‐Zn (~1.10 at. % solubility of Ag, 30 °C) is formed on the Ag coated Zn foil (Zn@Ag) and possesses the same crystal structure as Zn to reduce its nucleation barrier caused by their lattice mismatch. It merits oriented Zn deposition and corrosion‐resistant surface, and presents long cycling stability in symmetric cells and full cells coupled with V2O5 cathode. This work provides insights into interfacial regulation of Zn anodes for high‐performance aqueous zinc metal batteries. [ABSTRACT FROM AUTHOR]

Sodium-ion batteries (SIBs) are experiencing a large-scale renaissance to supplement or replace expensive lithium-ion batteries (LIBs) and low energy density lead-acid batteries in electrical energy storage systems and other applications. In this case, layered oxide materials have become one of the most popular cathode candidates for SIBs because of their low cost and comparatively facile synthesis method. However, the intrinsic shortcomings of layered oxide cathodes, which severely limit their commercialization process, urgently need to be addressed. In this review, inherent challenges associated with layered oxide cathodes for SIBs, such as their irreversible multiphase transition, poor air stability, and low energy density, are systematically summarized and discussed, together with strategies to overcome these dilemmas through bulk phase modulation, surface/interface modification, functional structure manipulation, and cationic and anionic redox optimization. Emphasis is placed on investigating variations in the chemical composition and structural configuration of layered oxide cathodes and how they affect the electrochemical behavior of the cathodes to illustrate how these issues can be addressed. The summary of failure mechanisms and corresponding modification strategies of layered oxide cathodes presented herein provides a valuable reference for scientific and practical issues related to the development of SIBs. [ABSTRACT FROM AUTHOR]

Alloying‐type antimony (Sb) with high theoretical capacity is a promising anode candidate for both lithium‐ion batteries (LIBs) and sodium‐ion batteries (SIBs). Given the larger radius of Na+ (1.02 Å) than Li+ (0.76 Å), it was generally believed that the Sb anode would experience even worse capacity degradation in SIBs due to more substantial volumetric variations during cycling when compared to LIBs. However, the Sb anode in SIBs unexpectedly exhibited both better electrochemical and structural stability than in LIBs, and the mechanistic reasons that underlie this performance discrepancy remain undiscovered. Here, using substantial in situ transmission electron microscopy, X‐ray diffraction, and Raman techniques complemented by theoretical simulations, we explicitly reveal that compared to the lithiation/delithiation process, sodiation/desodiation process of Sb anode displays a previously unexplored two‐stage alloying/dealloying mechanism with polycrystalline and amorphous phases as the intermediates featuring improved resilience to mechanical damage, contributing to superior cycling stability in SIBs. Additionally, the better mechanical properties and weaker atomic interaction of Na−Sb alloys than Li−Sb alloys favor enabling mitigated mechanical stress, accounting for enhanced structural stability as unveiled by theoretical simulations. Our finding delineates the mechanistic origins of enhanced cycling stability of Sb anode in SIBs with potential implications for other large‐volume‐change electrode materials. [ABSTRACT FROM AUTHOR]

Alloying‐type antimony (Sb) with high theoretical capacity is a promising anode candidate for both lithium‐ion batteries (LIBs) and sodium‐ion batteries (SIBs). Given the larger radius of Na+ (1.02 Å) than Li+ (0.76 Å), it was generally believed that the Sb anode would experience even worse capacity degradation in SIBs due to more substantial volumetric variations during cycling when compared to LIBs. However, the Sb anode in SIBs unexpectedly exhibited both better electrochemical and structural stability than in LIBs, and the mechanistic reasons that underlie this performance discrepancy remain undiscovered. Here, using substantial in situ transmission electron microscopy, X‐ray diffraction, and Raman techniques complemented by theoretical simulations, we explicitly reveal that compared to the lithiation/delithiation process, sodiation/desodiation process of Sb anode displays a previously unexplored two‐stage alloying/dealloying mechanism with polycrystalline and amorphous phases as the intermediates featuring improved resilience to mechanical damage, contributing to superior cycling stability in SIBs. Additionally, the better mechanical properties and weaker atomic interaction of Na−Sb alloys than Li−Sb alloys favor enabling mitigated mechanical stress, accounting for enhanced structural stability as unveiled by theoretical simulations. Our finding delineates the mechanistic origins of enhanced cycling stability of Sb anode in SIBs with potential implications for other large‐volume‐change electrode materials. [ABSTRACT FROM AUTHOR]

Sodium‐ion batteries (SIBs) with wide operating temperature are regarded as promising candidates for large‐scale energy storage systems. However, SIBs operating under elevated temperature aggravate the electrolyte decomposition with unstable cathode‐electrolyte interphase (CEI), causing a rapid capacity degradation. Herein, anion receptor tris(pentafluorophenyl)borane (TPFPB) is selected as electrolyte additive to construct robust NaF‐rich CEI. The strong interactions between anion and TPFPB via the electron‐deficient boron atoms weaken ClO4− solvation and promote the coordination capability between solvents and Na+ cations, demonstrating greatly improved oxidative stability. Na3V2(PO4)3 cathode in TPFPB‐containing electrolyte delivers long‐term stability with a capacity retention of 86.9% after 100 cycles at a high cut‐off voltage of 4.2 V (vs. Na+/Na) and a high temperature of 60 °C. Besides, TPFPB also works well with enhanced performance over a temperature range from −30 to 60 °C. This study proposes a prospective method by manipulating the solvation chemistry for constructing high‐temperature rechargeable SIBs. [ABSTRACT FROM AUTHOR]

Given the merits of affordable cost, superior low‐temperature performance, and advanced safe properties, sodium‐ion batteries (SIBs) have exhibited great development potential in large scale energy storage applications. Among various emerging carbonaceous anode materials applied for SIBs, hard carbon (HC) has recently gained significant attention regarding their relatively low cost, wide availability, and optimal overall performance. However, the insufficient initial Coulombic efficiency (ICE) of HC is the main bottlenecks, which is inevitably hindering their further commercial applications. Herein, an in‐depth holistic exposition about the reasons causing the unsatisfied ICE and the recent advances on effective improvement strategies are comprehensively summarized in this review, which have been divided into two aspects including the intrinsic property (degree of graphitization, pore structure, defect, et al.) and the extrinsic factor (electrolyte, electrode materials, et al.). In addition, future prospects and perspectives on HC to enable practical application in SIBs are also briefly outlined. [ABSTRACT FROM AUTHOR]

Sodium (Na) metal anodes are promising candidates for various batteries with high energy density and high‐power density, however, the dendrite growth of Na metal is impeding their practical applications. The binary alloy Na–K is in the liquid state at room temperature with a wide composition range, which renders it inherently free from solid dendrite growth. Whereas the application of Na–K alloy is plagued by the lack of a wettable matrix to immobilize the liquid metal. Herein, a facile method is reported to introduce oxygen‐rich functional groups into carbon fiber cloth (O‐CFC), which is initially Na–K phobic yet turns into superwetting after the treatment. The superwetting behavior of the O‐CFC can be attributed to the favorable enthalpy changes as a result of the introduction of O‐rich functional groups. The superwetting property of the O‐CFC exhibits good universality, which can be extended to melting Na and K metals. By adopting the superwetting O‐CFC as a host for liquid Na–K alloy, the liquid metal can be well retained in the matrix and deliver a stable cycling for >1600 h. The concept of enthalpy‐driven wettability regulation can be enlightening for the host material design of other liquid metals and alloys. [ABSTRACT FROM AUTHOR]

Sodium dual‐ion batteries (Na‐DIBs) have attracted increasing attention due to their high operative voltages and low‐cost raw materials. However, the practical applications of Na‐DIBs are still hindered by the issues, such as low capacity and poor Coulombic efficiency, which is highly correlated with the compatibility between electrode and electrolyte but rarely investigated. Herein, fluoroethylene carbonate (FEC) is introduced into the electrolyte to regulate cation/anion solvation structure and the stability of cathode/anode‐electrolyte interphase of Na‐DIBs. The FEC modulates the environment of PF6− solvation sheath and facilitates the interaction of PF6− on graphite. In addition, the NaF‐rich interphase caused by the preferential decomposition of FEC effectively inhibits side reactions and pulverization of anodes with the electrolyte. Consequently, Sb||graphite full cells in FEC‐containing electrolyte achieve an improved capacity, cycling stability and Coulombic efficiency. This work elucidates the underlying mechanism of bifunctional FEC and provides an alternative strategy of building high‐performance dual ion batteries. [ABSTRACT FROM AUTHOR]

Sodium dual‐ion batteries (Na‐DIBs) have attracted increasing attention due to their high operative voltages and low‐cost raw materials. However, the practical applications of Na‐DIBs are still hindered by the issues, such as low capacity and poor Coulombic efficiency, which is highly correlated with the compatibility between electrode and electrolyte but rarely investigated. Herein, fluoroethylene carbonate (FEC) is introduced into the electrolyte to regulate cation/anion solvation structure and the stability of cathode/anode‐electrolyte interphase of Na‐DIBs. The FEC modulates the environment of PF6− solvation sheath and facilitates the interaction of PF6− on graphite. In addition, the NaF‐rich interphase caused by the preferential decomposition of FEC effectively inhibits side reactions and pulverization of anodes with the electrolyte. Consequently, Sb||graphite full cells in FEC‐containing electrolyte achieve an improved capacity, cycling stability and Coulombic efficiency. This work elucidates the underlying mechanism of bifunctional FEC and provides an alternative strategy of building high‐performance dual ion batteries. [ABSTRACT FROM AUTHOR]

An abstract of the article "High Precision Charger to Investigate Spinel Li1+xMn2-x04 at Elevated Temperatures," by Shu-Lei Chou is presented.

High‐voltage lithium‐ion batteries (LIBs) have attracted great attention due to their promising high energy density. However, severe capacity degradation is witnessed, which originated from the incompatible and unstable electrolyte‐electrode interphase at high voltage. Herein, a robust additive‐induced sulfur‐rich interphase is constructed by introducing an additive with ultrahigh S‐content (34.04 %, methylene methyl disulfonate, MMDS) in 4.6 V LiNi0.5Co0.2Mn0.3O2 (NCM523)||graphite pouch cell. The MMDS does not directly participate the inner Li+ sheath, but the strong interactions between MMDS and PF6− anions promote the preferential decomposition of MMDS and broaden the oxidation stability, facilitating the formation of an ultrathin but robust sulfur‐rich interfacial layer. The electrolyte consumption, gas production, phase transformation and dissolution of transition metal ions were effectively inhibited. As expected, the 4.6 V NCM523||graphite pouch cell delivers a high capacity retention of 87.99 % even after 800 cycles. This work shares new insight into the sulfur‐rich additive‐induced electrolyte‐electrode interphase for stable high‐voltage LIBs. [ABSTRACT FROM AUTHOR]

High‐voltage lithium‐ion batteries (LIBs) have attracted great attention due to their promising high energy density. However, severe capacity degradation is witnessed, which originated from the incompatible and unstable electrolyte‐electrode interphase at high voltage. Herein, a robust additive‐induced sulfur‐rich interphase is constructed by introducing an additive with ultrahigh S‐content (34.04 %, methylene methyl disulfonate, MMDS) in 4.6 V LiNi0.5Co0.2Mn0.3O2 (NCM523)||graphite pouch cell. The MMDS does not directly participate the inner Li+ sheath, but the strong interactions between MMDS and PF6− anions promote the preferential decomposition of MMDS and broaden the oxidation stability, facilitating the formation of an ultrathin but robust sulfur‐rich interfacial layer. The electrolyte consumption, gas production, phase transformation and dissolution of transition metal ions were effectively inhibited. As expected, the 4.6 V NCM523||graphite pouch cell delivers a high capacity retention of 87.99 % even after 800 cycles. This work shares new insight into the sulfur‐rich additive‐induced electrolyte‐electrode interphase for stable high‐voltage LIBs. [ABSTRACT FROM AUTHOR]

As a class of promising cathodes in the field of large-scale power storage systems especially for alkali-metal-ion batteries (MIBs), Prussian blue (PB) and its analogues (PBAs) have received wide research attention due to their open framework, high theoretical specific capacity, and simple synthesis method. For large-scale applications, cathode materials with low-cost and long cycle life are preferred. However, only a few of the review papers have concentrated on the detailed analysis of low-cost PBAs, including Fe-based and Mn-based PBAs, which also show excellent electrochemical performance. This review aims to first provide an all-sided understanding of low-cost PBAs in terms of their application and recent progress in MIBs. Then, the major challenges such as inferior electrochemical properties of low-cost PBAs are discussed. Meanwhile, we provide feasible strategies to prepare PBA electrodes with advanced electrochemical performance. Finally, we present some personal perspectives and guidance for future research, aiming to narrow the gap between laboratory investigation and practical application. [ABSTRACT FROM AUTHOR]

Prussian blue analogues (PBAs) have been regarded as promising cathode materials for alkali‐ion batteries owing to their high theoretical energy density and low cost. However, the high water and vacancy content of PBAs lower their energy density and bring safety issues, impeding their large‐scale application. Herein, a facile "potassium‐ions assisted" strategy is proposed to synthesize highly crystallized PBAs. By manipulating the dominant crystal plane and suppressing vacancies, the as‐prepared PBAs exhibit increased redox potential resulting in high energy density up to ≈450 Wh kg−1, which is at the same level of the well‐known LiFePO4 cathodes for lithium‐ion batteries. Remarkably, unconventional highly‐reversible phase evolution and redox‐active pairs were identified by multiple in situ techniques for the first time. The preferred guest‐ion storage sites and migration mechanism were systematically analysed through theoretical calculations. We believe these results could inspire the design of safe with high energy density. [ABSTRACT FROM AUTHOR]

Prussian blue analogues (PBAs) have been regarded as promising cathode materials for alkali‐ion batteries owing to their high theoretical energy density and low cost. However, the high water and vacancy content of PBAs lower their energy density and bring safety issues, impeding their large‐scale application. Herein, a facile "potassium‐ions assisted" strategy is proposed to synthesize highly crystallized PBAs. By manipulating the dominant crystal plane and suppressing vacancies, the as‐prepared PBAs exhibit increased redox potential resulting in high energy density up to ≈450 Wh kg−1, which is at the same level of the well‐known LiFePO4 cathodes for lithium‐ion batteries. Remarkably, unconventional highly‐reversible phase evolution and redox‐active pairs were identified by multiple in situ techniques for the first time. The preferred guest‐ion storage sites and migration mechanism were systematically analysed through theoretical calculations. We believe these results could inspire the design of safe with high energy density. [ABSTRACT FROM AUTHOR]

FeP is prepared in large quantities by ball milling of stoichiometric mixtures of the elements for 20 h. [ABSTRACT FROM AUTHOR]

Correction for ‘A new, cheap, and productive FeP anode material for sodium-ion batteries’ by Wei-Jie Li et al., Chem. Commun., 2015, DOI: URL10.1039/c4cc09604e/URL. [ABSTRACT FROM AUTHOR]

A composite of manganese monoxide loaded onto carbon nanotubes (CNTs@MnO) has been synthesized by a facile approach, in which the CNTs form a continuous conductive network connecting the electrocatalyst MnO nanoparticles together to facilitate good electrochemical performance. The electrocatalyst MnO shows favourable rechargeability, and good phase and morphology stability in lithium oxygen batteries. Excellent cycling performance is also demonstrated, in which the terminal voltage is higher than 2.4 V after 100 cycles at 0.4 mA cm−2, with 1000 mAh g−1(composite) capacity. Therefore, this hybrid material is promising for use as a cathode material for lithium oxygen batteries. [ABSTRACT FROM AUTHOR]

Abstract: Sodium‐ion batteries (SIBs) have been considered as the most promising candidate for large‐scale energy storage system owing to the economic efficiency resulting from abundant sodium resources, superior safety, and similar chemical properties to the commercial lithium‐ion battery. Despite the long period of academic research, how to realize sodium‐ion battery commercialization for market applications is still a great challenge. Thus, from the perspective of future practical application, this review will identify the factors that are restricting commercialization, and evaluate the existing active materials and sodium‐ion‐based full‐cell system. The design and development trends that are needed for SIBs to meet the requirements of practical applications in large‐scale energy storage will also be discussed in detail. [ABSTRACT FROM AUTHOR]

The non-aqueous lithium oxygen battery has been considered as one of the most promising energy storage systems owing to its potentially high energy density, exceeding that of any other existing storage system for storing sustainable and clean energy. The success of Li-O2 batteries could efficiently reduce greenhouse gas emissions and the consumption of non-renewable fossil fuels. How to achieve high round-trip efficiency, high capacity, and satisfactory cycling performance, however, is still a great challenge for the lithium oxygen battery. Thus, this report will point out what factors will affect the electrochemical performance and will aim to describe how to increase the electrochemical performance by air electrode optimization. Based on recent achievements, several approaches to solving this problem, such as synthesizing electrocatalysts with high catalytic activity and designing appropriate air electrode structures, are described in details. Also, recent progress associated with novel air electrode designs and understanding the reaction process is discussed. [ABSTRACT FROM AUTHOR]

The development of large‐scale energy storage systems (ESSs) aimed at application in renewable electricity sources and in smart grids is expected to address energy shortage and environmental issues. Sodium‐ion batteries (SIBs) exhibit remarkable potential for large‐scale ESSs because of the high richness and accessibility of sodium reserves. Using low‐cost and abundant elements in cathodes with long cycling stability is preferable for lowering expenses on cathodes. Many investigated cathodes for SIBs are dogged by structural and morphology changes, unstable interphases between the cathode and the electrolyte, and air sensitivity, causing unsatisfactory cycling performance. Therefore, understanding the mechanism of capacity degeneration in depth and developing precise solutions are critical for designing low‐cost cathodes that are highly stable under cycling. Herein, recent progress in long‐cycle‐life and low‐cost cathodes for SIBs is focused on, and a comprehensive discussion of the key points in SIBs toward large‐scale applications is provided. The roots of the unstable cycling performance of low‐cost cathodes are discussed. Also, effective strategies are summarized from the recent progress on long‐cycle‐life and low‐cost cathodes. This review is expected to encourage deeper investigation of long‐lifespan cathodes for SIBs, particularly for potential large‐scale industrialization. [ABSTRACT FROM AUTHOR]

Hard carbon (HC) anodes have shown extraordinary promise for sodium‐ion batteries, but are limited to their poor initial coulombic efficiency (ICE) and low practical specific capacity due to the large amount of defects. These defects with oxygen containing groups cause irreversible sites for Na+ ions. Highly graphited carbon decreases defects, while potentially blocking diffusion paths of Na+ ions. Therefore, molecular‐level control of graphitization of hard carbon with open accessible channels for Na+ ions is key to achieve high‐performance hard carbon. Moreover, it is challenging to design a conventional method to obtain HCs with both high ICE and capacity. Herein, a universal strategy is developed as manganese ions‐assisted catalytic carbonization to precisely tune graphitization degree, eliminate defects, and maintain effective Na+ ions paths. The as‐prepared hard carbon has a high ICE of 92.05% and excellent cycling performance. Simultaneously, a sodium storage mechanism of "adsorption‐intercalation‐pore filling‐sodium cluster formation" is proposed, and a clear description given of the boundaries of the pore structure and the specific dynamic process of pore filling. [ABSTRACT FROM AUTHOR]