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Highlights: Proposing a one-step pyrolysis strategy to fabricate a novel bilayer-shelled N, O-doped hollow porous carbon microspheres (NOHPC) anode. The optimized NOHPC anode displays a high K-storage capacity of 325.9 mAh g−1 at 0.1 A g−1 and excellent rate performance (201.1 mAh g−1 at 5 A g−1 after 6000 cycles). The assembled NOHPC//hollow porous activated carbon microspheres (HPAC) potassium ion hybrid capacitors deliver a high energy density of 90.1 Wh kg−1 at a power density of 939.6 W kg−1 even over 6000 cycles. With the advantages of high energy/power density, long cycling life and low cost, dual-carbon potassium ion hybrid capacitors (PIHCs) have great potential in the field of energy storage. Here, a novel bilayer-shelled N, O-doped hollow porous carbon microspheres (NOHPC) anode has been prepared by a self-template method, which is consisted of a dense thin shell and a hollow porous spherical core. Excitingly, the NOHPC anode possesses a high K-storage capacity of 325.9 mA h g−1 at 0.1 A g−1 and a capacity of 201.1 mAh g−1 at 5 A g−1 after 6000 cycles. In combination with ex situ characterizations and density functional theory calculations, the high reversible capacity has been demonstrated to be attributed to the co-doping of N/O heteroatoms and porous structure improved K+ adsorption and intercalation capabilities, and the stable long-cycling performance originating from the bilayer-shelled hollow porous carbon sphere structure. Meanwhile, the hollow porous activated carbon microspheres (HPAC) cathode with a high specific surface area (1472.65 m2 g−1) deriving from etching NOHPC with KOH, contributing to a high electrochemical adsorption capacity of 71.2 mAh g−1 at 1 A g−1. Notably, the NOHPC//HPAC PIHC delivers a high energy density of 90.1 Wh kg−1 at a power density of 939.6 W kg−1 after 6000 consecutive charge–discharge cycles. [ABSTRACT FROM AUTHOR]

Sodium‐ion batteries show promising potential for large‐scale energy storage. However, the large size and heavy mass of Na+ always results in huge volume change and inferior electrochemical stability, especially in alloy‐type anode materials. Here, molecular engineering of the polymer binders, i.e., cross‐linking of poly(acrylic acid) with glycerin (PAA‐GLY), reinforces the mechanical properties, eliminates the active protons of PAA, and benefits electrolyte diffusion, thereby remarkably improving electrochemical performance. Using µ‐Sn as an example, the cycle life at 2 A g−1 is extended from ≈26 cycles of PAA to ≈2000 cycles of PAA‐GLY. Meanwhile, the initial Coulombic efficiency is promoted to 90.3%, allowing the fabrication step of electrode presodiation for full cells to be eliminated. Thus, the full cells run 300 cycles at 2 A g−1. In addition, the binder allows the thick electrode to exhibit an areal capacity of 6.8 mAh cm−2. This binder is also applied for µ‐Bi and µ‐Sb. The simple operation, remarkable improvement, and wide applications indicate the promising prospects of this strategy for advanced electrodes in sodium ion batteries. [ABSTRACT FROM AUTHOR]

Regulating lithium deposition/stripping behavior in 3D hosts is critical for the development of stable lithium metal batteries. Herein, a low‐tortuosity wood derived carbon (WDC) with gradient‐distributed lithiophilic sites is rationally constructed via biomimetic capillary action, as an efficient scaffold for lithium deposition/stripping. Due to the merits of excellent spatial controllability, the gradient Ag particles modified WDC (WDC‐GDAg) displays favorable bottom‐up Li plating behavior with high columbic efficiency and long cycling stability. Finite element simulation reveals that gradient‐distributed Ag sites enable high lithium flux distribution at the bottom and homogeneous electric field distribution on the top of the WDC electrode. Moreover, the full cells with a WDC‐GDAg anode and a LiFePO4 cathode demonstrate high capacity retention of ≈78.9% after 2000 cycles at 10 C and remarkable rate performance even at 40 C, presenting great potential for practical applications. [ABSTRACT FROM AUTHOR]

Aqueous rechargeable zinc ion batteries have received widespread attention due to their high energy density and low cost. However, zinc metal anodes face fatal dendrite growth and detrimental side reactions, which affect the cycle stability and practical application of zinc ion batteries. Here, an in-situ formed hierarchical solid-electrolyte interphase composed of InF3, In, and ZnF2 layers with outside-in orientation on the Zn anode (denoted as Zn@InF3) is developed by a sample InF3 coating. The inner ultrathin ZnF2 interface between Zn anode and InF3 layer formed by the spontaneous galvanic replacement reaction between InF3 and Zn, is conductive to achieving uniform Zn deposition and inhibits the growth of Zinc dendrites due to the high electrical resistivity and Zn2+ conductivity. Meanwhile, the middle uniformly generated metallic In and outside InF3 layers functioning as corrosion inhibitor suppressing the side reaction due to the waterproof surfaces, good chemical inactivity, and high hydrogen evolution overpotential. Besides, the as-prepared zinc anode enables dendrite-free Zn plating/stripping for more than 6,000 h at nearly 100% coulombic efficiency (CE). Furthermore, coupled with the MnO2 cathode, the full battery exhibits the long cycle of up to 1,000 cycles with a low negative-to-positive electrode capacity (N/P) ratio of 2.8. [ABSTRACT FROM AUTHOR]

Uncontrollable lithium dendrite growth which typically results in poor cycling stability and safety issues remains a great challenge for lithium metal batteries. Herein, we report a novel separator modification strategy by using polydimethylsiloxane (PDMS) to functionalize a glass fiber separator to inhibit dendrite growth. The PDMS-modified separator not only acts as a mechanical barrier but also promotes the desolvation of lithium ions. Consequently, Li/Li symmetric cells with optimal PDMS-modified separators are able to stably cycle for more than 1200 hours at 2 mA cm−2 with a stable polarization voltage (about 60 mV). Moreover, with the assistance of the functionalized separator, the assembled Li/LiFePO4 full cell can impressively achieve capacity retention up to 82.5% and a coulombic efficiency of ∼99.4% after 200 cycles at 1.0 C. The PDMS functionalization strategy provides a simple and efficient approach for developing safe and high-performance lithium metal batteries. [ABSTRACT FROM AUTHOR]

Red phosphorus (RP), with high theoretical specific capacity and low working potential, has been regarded as one of the most promising anodes for high‐performance sodium‐ion batteries (SIBs). However, the unsatisfactory performance of RP anodes especially under high mass loading conditions severely limited the development for practical applications, due to its large volume variations during cycling processes, and the poor electronic and ionic conductivity. Here, a hierarchical WDC/CNTs@RP electrode with high mass loadings of RP (up to 14.1 mg cm−2) and superior conductivity is rationally designed for both ions and electrons. Such unique hierarchical structures enable an unprecedented rate performance (1.63 mAh cm−2 under 106.6 mA cm−2), long cycling life, and a decent gravimetric capacity of 468.88 mA h g−1 based on the whole electrode and inactive components. This work presents an essential step toward practical applications of RP anode materials for SIBs batteries. [ABSTRACT FROM AUTHOR]

The aqueous rechargeable sodium‐ion battery (ARSIB) is considered to be the most promising candidate for large‐scale energy storage applications, due to its low cost, safety, and eco‐friendliness. However, the poor cycle life and low energy density of ARSIB impede its practical applications. In this context, hollow NaTi2(PO4)3 nanocubes anode is engineered through a facile, low‐cost, and large‐scale hydrothermal approach. Na0.44MnO2 cathode delivers a high capacity of 75.16 mAh g−1 with the compensation of sodium ions by the zinc metal‐induced pre‐sodiation of the anode in a deep eutectic electrolyte. The well‐designed structure in hollow carbon‐coated NaTi2(PO4)3 nanocubes enables high stability and rate performance. Moreover, the adoption of deep eutectic electrolytes can minimize the Mn dissolution in the Na0.44MnO2 cathode. When coupling the cathode and anode, the as‐assembled ARSIB with a deep eutectic electrolyte exhibits an ultralong cycle life up to 3500 cycles (with capacity retention of 90%), an ultrahigh energy density of 50.0 Wh kg−1, and superior rate capability (maximum power density of 1500 W kg−1). This ARSIB represents an alternative promising candidate for large‐scale electrochemical energy storage. [ABSTRACT FROM AUTHOR]

Promoting the solution phase formation of Li2O2 rather than on the cathode surface is a key issue for high‐performance Li–O2 batteries. Protic additives have been reported to guide the discharge of Li2O2 in the electrolyte solution, while further advances are stalled by the intrinsical reactivity to Li metal to deteriorate the lifespan of Li–O2 batteries. Herein, rhodamine B (RhB), a protic additive, is first introduced into electrolyte as a phase‐transfer catalyst to achieve solution phase formation of Li2O2. The yield of Li2O2 is 90.79%, and the discharge capacity is 46 000 mAh gcarbon−1 at current density of 1000 mA gcarbon−1, which is 23‐fold higher than that of blank electrolyte. Density functional theory calculations further demonstrate the feasibility of RhB to boost solution phase discharge. Most notably, the free chlorine ion in RhB assists the in situ formation of a stable Li+‐conducting solid electrolyte interphase to protect Li anode from corrosion and dendrite formation during cycling. As a result, Li||Li symmetric cells exhibit a long cycle performance up to 1300 h at 1 mA cm−2 with low hysteresis voltage. Benefiting from the above results, Li–O2 batteries with RhB present long cycle stability. [ABSTRACT FROM AUTHOR]

In the past decades, the world has witnessed the successful commercialization of "rocking‐chair"‐type lithium‐ion batteries with lithium metal free anodes. Owing to their safe, green, easy manufacturing, and cost‐efficiency characteristics, rechargeable zinc batteries have recently received more and more attention. However, the practical application of Zn metal batteries is hampered mainly by the dendritic growth of Zn metal anode, which leads to poor Coulombic efficiency, hazards, and various side reactions. Herein, the emerging "rocking‐chair"‐type Zn‐ion batteries are systemically reviewed with Zn host anodes instead of Zn metal anodes. As an introduction, the fundamental principles, advantages, and challenges of "rocking‐chair"‐type Zn‐ion batteries are discussed. Subsequently, the design principles and recent advances of cathode, anode, and electrolyte for "rocking‐chair" Zn‐ion batteries are summarized. To conclude, perspectives on the future of "rocking‐chair" Zn‐ion batteries are presented. It is hoped that this review may provide alternative directions for the design of Zn‐ion batteries. [ABSTRACT FROM AUTHOR]

Ti-based anode materials in sodium ion batteries have attracted extensive interests due to its abundant resources, low toxicity, easy synthesis and long cycle life. However, low Coulombic efficiency and limited specific capacity affect their applications. Here, cubic-phase TiP2O7 is examined as anode materials, using in-situ/ex-situ characterization techniques. It is concluded that the redox reactions of Ti4+/Ti3+ and Ti3+/Ti0 consecutively occur during the discharge/charge processes, both of which are highly reversible. These reactions make the specific capacity of TiP2O7 even higher than the case of TiO2 that only contains a simple anion, O2−. Interestingly, Ti species participate only one of the redox reactions, due to the remarkable difference in local structures related to the sodiation process. The stable discharge/charge products in TiP2O7 reduce the side reactions and improve the Coulombic efficiency as compared to TiO2. These features make it a promising Ti-based anode for sodium ion batteries. Therefore, TiP2O7@C microflowers exhibit excellent electrochemical performances, ~ 109 mAh·g−1 after 10,000 cycles at 2 A·g−1, or 95.2 mAh·g−1 at 10 A·g−1. The results demonstrate new opportunities for advanced Ti-based anodes in sodium ion batteries. [ABSTRACT FROM AUTHOR]

A fast ion conductor, NaTi2(PO4)3 (NTP), is hydrothermally synthesized as a solid‐state electrolyte protection layer on the surface of Zn anodes (NTP@Zn). NTP has fast ionic conductivity compared with other insoluble phosphates, such as TiP2O7 (TPO) and Zn3(PO4)2 (ZPO), which is demonstrated by the density‐functional theory calculation and cyclic voltammetry tests. X‐ray photoelectron spectrometer, X‐ray powder diffraction, and HRTEM analyses show that the internal transport/mobility of Zn2+ can be achieved in NTP layer as an "ion passable fence." The NTP layer with a thickness of 20–25 µm not only prevents side reactions and zinc dendrites, but also improves the reversibility of Zn deposition and electrochemical performance. The NTP@Zn/MnO2 battery represents the best long‐life performance among Zn/MnO2 batteries to date, which successfully retains a considerable capacity of 105 mA h g−1 with a CE nearly 100% after 10 000 charge/discharge cycles at 10 C (≈1.5 A g−1). Each cycle capacity attenuation rate is only 0.004%. This work represents an advanced step toward long‐life Zn metal anodes for aqueous zinc‐ion batteries. [ABSTRACT FROM AUTHOR]

Metal anodes based on a plating/stripping electrochemistry such as metallic Li, Na, K, Zn, Mg, Ca, Al, and Fe have attracted widespread attention over the past several years because of their high theoretical specific capacity, low electrochemical potential, and superior electronic conductivity. Metal anodes can be paired with cathodes to construct high‐energy‐density rechargeable metal batteries. However, inherent issues including large volume changes, uncontrollable growth of dangerous dendrites, and an unstable solid electrolyte interphase (SEI) hinder their further development. MXene as an emerging 2D material has shown great potential to address the inherent issues of metal anodes due to its 2D structure, abundant surface functional groups, and the ability to construct macroscopic architectures. To date, under the assistance of MXene, various strategies have been proposed to achieve stable and dendrite‐free metal anodes, such as MXene‐based host design, designing metalphilic MXene‐based substrates, modifying the metal surface with MXene, constructing MXene arrays, and decorating separators or electrolytes with MXene. Herein the applications and advances of MXene in stable and dendrite‐free metal anodes are carefully summarized and analyzed. Some perspectives and outlooks for future research are also proposed. [ABSTRACT FROM AUTHOR]

Hollow nanospheres are desirable to resolve the volume expansion of red phosphorus anodes for sodium-ion batteries. Here, we developed a mild molten salt method to prepare hollow red phosphorus in the NaCl–KCl–AlCl3 system by using the Kirkendall effect. As an anode for sodium-ion batteries, the prepared hollow nanospheres exhibit a highly reversible capacity of 624 mA h g−1 at 4.0C and 737 mA h g−1 at 1.0C even after 600 cycles with a low capacity fading rate of 0.06% per cycle. [ABSTRACT FROM AUTHOR]

Aqueous lithium/sodium‐ion batteries (AIBs) have received increasing attention because of their intrinsic safety. However, the narrow electrochemical stability window (1.23 V) of the aqueous electrolyte significantly hinders the development of AIBs, especially the choice of electrode materials. Here, an aqueous electrolyte composed of LiClO4, urea, and H2O, which allows the electrochemical stability window to be expanded to 3.0 V, is developed. Novel [Li (H2O)x(organic)y]+ primary solvation sheath structures are developed in this aqueous electrolyte, which contribute to the formation of solid–electrolyte interface layers on the surfaces of both the cathode and anode. The expanded electrochemical stability window enables the construction of full aqueous Li‐ion batteries with LiMn2O4 cathodes and Mo6S8 anodes, demonstrating an operating voltage of 2.1 V and stability over 2000 cycles. Furthermore, a symmetric aqueous Na‐ion battery using Na3V2(PO4)3 as both the cathode and anode exhibits operating voltage of 1.7 V and stability over 1000 cycles at a rate of 5 C. [ABSTRACT FROM AUTHOR]

Silicon (Si) and lithium metal are the most favorable anodes for high‐energy‐density lithium‐based batteries. However, large volume expansion and low electrical conductivity restrict commercialization of Si anodes, while dendrite formation prohibits the applications of lithium‐metal anodes. Here, uniform nanoporous Si@carbon (NPSi@C) from commercial alloy and CO2 is fabricated and tested as a stable anode for lithium‐ion batteries (LIBs). The porosity of Si as well as graphitization degree and thickness of the carbon layer can be controlled by adjusting reaction conditions. The rationally designed porosity and carbon layer of NPSi@C can improve electronic conductivity and buffer volume change of Si without destroying the carbon layer or disrupting the solid electrolyte interface layer. The optimized NPSi@C anode shows a stable cyclability with 0.00685% capacity decay per cycle at 5 A g−1 over 2000 cycles for LIBs. The energy storage mechanism is explored by quantitative kinetics analysis and proven to be a capacitance‐battery dual model. Moreover, a novel 2D/3D structure is designed by combining MXene and NPSi@C. As lithiophilic nucleation seeds, NPSi@C can induce uniform Li deposition with buffered volume expansion, which is proven by exploring Li‐metal deposition morphology on Cu foil and MXene@NPSi@C. The practical potential application of NPSi@C and MXene@NPSi@C is evaluated by full cell tests with a Li(Ni0.8Co0.1Mn0.1)O2 cathode. [ABSTRACT FROM AUTHOR]

MoSe2 grown on N,P-co-doped carbon nanosheets is synthesized by a solvothermal reaction followed with a high-temperature calcination. This composite has an interlayer spacing of MoSe2 expanded to facilitate sodium-ion diffusion, MoSe2 immobilized on carbon nanosheets to improve charge-transfer kinetics, and N and P incorporated into carbon to enhance its interaction with active species upon cycling. These features greatly improve the electrochemical performance of this composite, as compared to all the controls. It presents a specific capacity of 378 mAh g−1 after 1000 cycles at 0.5 A g−1, corresponding to 87% of the capacity at the second cycle. Ex situ Raman spectra and high-resolution transmission electron microscopy images confirm that it is element Se, rather than MoSe2, formed after the charging process. The interaction of the active species with modified carbon is simulated using density functional theory to explain this excellent stability. The superior rate capability, where the capacity at 15 A g−1 equals ≈55% of that at 0.5 A g−1, could be associated with the significant contribution of pseudocapacitance. By pairing with homemade Na3V2(PO4)3/C, this composite also exhibits excellent performances in full cells. [ABSTRACT FROM AUTHOR]

Porous electrode materials with large specifi c surface area, relatively short diffusion path, and higher electrical conductivity, which display both better rate capabilities and good cycle lives, have huge benefi ts for practical applications in lithium-ion batteries. Here, uniform porous NiCo2O4 nanorods (PNNs) with pore-size distribution in the range of 10-30 nm and lengths of up to several micrometers are synthesized through a convenient oxalate co-precipitation method followed by a calcining process. The PNN electrode exhibits high reversible capacity and outstanding cycling stability (after 150 cycles still maintain about 650 mA h g-1 at a current density of 100 mA g-1 ), as well as high Coulombic effi ciency (>98%). Moreover, the PNNs also exhibit an excellent rate performance, and deliver a stable reversible specifi c capacity of 450 mA h g-1 even at 2000 mA g-1 . These results demonstrate that the PNNs are promising anode materials for high-performance Li-ion batteries. [ABSTRACT FROM AUTHOR]

Hollow structures of transition-metal oxides, particularly mixed-metal oxides, could be promising for various applications such as lithium-ion batteries (LIBs). Compared to the synthesis of metal oxide hollow spheres by the template method, non-spherical metal oxide hollow hexagonal polyhedra have not been developed to date. Herein, we report the controlled hydrothermal synthesis of a new phase of Co3V2O8⋅ n H2O hollow hexagonal prismatic pencils (HHPPs), which is composed of uniform structural units. By varying the amount of NaOH in the presence of NH4+ and without any template or organic surfactant, the hexagonal prismatic pencils gradually transform from solid into hollow structures, with sizes varying from 5 to 20 μm. The structure of pencils can be preserved only in a limited range of the molar ratio of OH−/NH4+. As a new anode material for LIBs, such hollow pencils exhibit impressive lithium storage properties with high capacity, good cycling stability, and superior rate capability. [ABSTRACT FROM AUTHOR]

A facile two-step strategy involving a polyol method and subsequent thermal annealing treatment is successfully developed for the large-scale preparation of ZnCo2O4 various hierarchical micro/nanostructures (twin mcrospheres and microcubes) without surfactant assistance. To the best of our knowledge, this is the first report on the synthesis of ZnCo2O4 mesoporous twin microspheres and microcubes. More significantly, based on the effect of the reaction time on the morphology evolution of the precursor, a brand-new crystal growth mechanism, multistep splitting then in situ dissolution recrystallization accompanied by morphology and phase change, is first proposed to understand the formation of the 3D twin microshperes, providing new research opportunity for investigating the formation of novel micro/nanostructures. When evaluated as anode materials for lithium-ion batteries (LIBs), ZnCo2O4 hierarchical microstructures exhibit superior capacity retention, excellent cycling stability at the 5 A g−1 rate for 2000 cycles. Surprisingly, the ZnCo2O4 twin microspheres show an exceptionally high rate capability up to the 10 A g−1 rate. It should be noted that such super-high rate performance and cycling stability at such high charge/discharge rates are significantly higher than most work previously reported on ZnCo2O4 micro/nanostructures and ZnCo2O4-based heterostructures. The ZnCo2O4 3D hierarchical micro/nanostructures demonstrate the great potential as negative electrode materials for high-performance LIBs. [ABSTRACT FROM AUTHOR]

A new thread for improving the cycling stability of Fe2O3 nanorice is proposed through combining the electrochemical porousness (EP) effect and solid-electrolyte interphase (SEI) thermolysis approach. Starting from solid Fe2O3 nanorice, this process could be applied to prepare porous Fe2O3 nanorice with a good coating of a porous SEI thermolysis layer composed of carbon and Li2O. The interconnecting pores and full coating of the SEI thermolysis layer provides not only mechanical resistance of the Fe2O3 nanorice against pulverization, but also high electrical and ionic conductivity over the electrode throughout long cell cycles. This method results in the enhancement of cycling ability and capacity, which is demonstrated by comparison with the starting Fe2O3 nanorice. After the EP and SEI thermolysis approach, the Fe2O3 nanorice exhibits an energy capacity retention about of 680 mAhg-1 at a current density of 1000 mAg-1 over 250 cycles, which is more than 82% of the initial reversible capacity. Moreover, it also has an excellent rate capability and high coulombic efficiency. This strategy provides a simple and convenient route toward stable charge/discharge cycling for not only Fe2O3, but also for other electrode materials that are subject to large volume changes and low charge voltages. At the same time, it also contributes to a fundamental understanding of improved cycling stability and reversible capacity for electrode materials. [ABSTRACT FROM AUTHOR]

A facile method is presented for the large-scale preparation of rationally designed mesocrystalline MnO@carbon core-shell nanowires with a jointed appearance. The nanostructures have a unique arrangement of internally encapsulated highly oriented and interconnected MnO nanorods and graphitized carbon layers forming an external coating. Based on a comparison and analysis of the crystal structures of MnOOH, Mn2O3, and MnO@C, we propose a sequential topotactic transformation of the corresponding precursors to the products. Very interestingly, the individual mesoporous single-crystalline MnO nanorods are strongly interconnected and maintain the same crystallographic orientation, which is a typical feature of mesocrystals. When tested for their applicability to Li-ion batteries (LIB), the MnO@carbon core-shell nanowires showed excellent capacity retention, superior cycling performance, and high rate capability. Specifically, the MnO@carbon core-shell nanostructures could deliver reversible capacities as high as 801 mA h g−1 at a high current density of 500 mA g−1, with excellent electrochemical stability after testing over 200 cycles, indicating their potential application in LIBs. The remarkable electrochemical performance can mainly be attributed to the highly uniform carbon layer around the MnO nanowires, which is not only effective in buffering the structural strain and volume variations of anodes during repeated electrochemical reactions, but also greatly enhances the conductivity of the electrode material. Our results confirm the feasibility of using these rationally designed composite materials for practical applications. The present strategy is simple but very effective, and appears to be sufficiently versatile to be extended to other high-capacity electrode materials with large volume variations and low electrical conductivities. [ABSTRACT FROM AUTHOR]

Graphene-wrapped FeO nanorings (RGO/FeO) were synthesized by a facile approach, which assembled with graphene and the FeO nanorings precursor through the colloidal coagulation effect at room temperature. The uniform FeO nanorings prepared by hydrothermal routes were homogeneously distributed and well wrapped by graphene. When tested as anode for lithium ion batteries, RGO/FeO exhibits a high capacity and good cycling stability. This could be attributed to the interaction of ring-shaped structure and graphene sheets, which inherit the good kinetic property of FeO nanorings and enhance the structural integrity with graphene sheets' support. [ABSTRACT FROM AUTHOR]

Rocking Chair Batteries: Recent Advances and Perspectives of Zn-Metal Free "Rocking-Chair"-Type Zn-Ion Batteries (Adv. The fundamental principles, advantages, challenges and recent advances of Zn-metal free "rocking-chair"-type Zn-ion batteries are summarized and discussed. Dendrites, electrolytes, "rocking-chair" Zn-ion batteries, Zn-metal free anodes, Zn-rich cathodes. [Extracted from the article]

Keywords: controlled fabrication; lithium-ion batteries; lithium-metal batteries; MXene; silicon@carbon anodes In article number 1908721, Jinkui Feng and co-workers fabricate uniform nanoporous silicon@carbon (NPSi@C) from commercial alloy and CO SB 2 sb is fabricated as the anode for lithium ion batteries. Controlled fabrication, lithium-ion batteries, lithium-metal batteries, MXene, silicon@carbon anodes. [Extracted from the article]

NiO polyhedron nanocrystals have been synthesized using a single source of nickel chloride through a calcination reaction. The electrochemical results displayed that the obtained sample is an outstanding anode material for lithium ion batteries (LIBs). The sample maintains a high specific capacity of 645.5 mAh g −1 at current density of 1000 mA g −1 after 100 cycles. Even at high current density of 4000 mA g −1 , the NiO polyhedron nanocrystals still deliver a capacity of 459.6 mAh g −1 . The high specific capacity, long stable cyclic property and good rate capability make the NiO polyhedron nanocrystals a good candidate anode material for high-performance LIBs. [ABSTRACT FROM AUTHOR]

Abstract: Well dispersed chestnut-like Cd2Ge2O6 (CGO) and Cd2Ge2O6/reduced graphene oxide (CGO/RGO) nanocomposites are successfully prepared via a facile one-pot hydrothermal method and characterized as novel lithium storage materials for the first time. Electrochemical characterization of lithiation/delithiation of the CGO/RGO nanocomposites reveals a large capacity of 943mAhg−1 for the first cycle and a capacity retention of 721mAhg−1 even after 100 cycles. The superior electrochemical performance of the CGO/RGO nanocomposites electrode compared to the pure CGO electrode can be attributed to the well dispersed RGO which enhances the electronic conductivity and accommodate the volume change during the lithium storage process. [Copyright &y& Elsevier]

SiO x is a promising anode material for lithium-ion batteries owing to its smaller volume expansion and longer lifespan than silicon. However, its development is severely hampered by the sluggish reaction kinetics and large volume changes. Herein, a facile and scalable synthesis of exfoliated N-doped carbon nanoslices supported SiO x (SiO x /NCS) is developed by a melamine assisted ball milling and annealing procedure. The principle of melamine in exfoliating graphite is demonstrated by contrast experiments and theoretical calculations. It is found NCS acts as matrix to enhance the reaction kinetics and accommodate the volume changes which contributes to the significant improvements of cycling performance and rate capability. The SiO x /NCS anode exhibits ultrastable cycling performance (∼900 mAh g−1 over 600 cycles at 1 A g−1) and superior rate capability (565 mAh g−1 at 5 A g−1). At a high mass loading of 3.3 mg cm−2, an ultrahigh areal capacity of 2.4 mAh cm−2 is obtained after 200 cycles. Moreover, the potential application of SiO x /NCS anode in LIBs is also confirmed by the good performance of SiO x /NCS//NCM111 full cells. [Display omitted] • SiO x /NCS composite is synthesized via a facile and scalable route. • The principle of melamine in exfoliating graphite is theoretically demonstrated. • SiO x /NCS composite exhibits ∼900 mAh g−1 over 600 cycles at 1.0 A g−1. • SiO x /NCS shows high areal capacity of 2.4 mAh cm−2 at 3.3 mg cm−2 after 200 cycles. [ABSTRACT FROM AUTHOR]

• Li 3 VO 4 nanoparticles in porous N-doped carbon are synthesized. • Porous N-doped carbon is derived from melamine and citric acid. • Porous N-doped carbon and Li 3 VO 4 nanoparticles together give superior performances. • This composite exhibits a capacity of 236.6 mAh g−1 after 1000 cycles at 4.0 A g−1. • This composite coupled with LiCoO 2 as full cells are examined. Li 3 VO 4 nanoparticles in N-doped carbon with porous structure are synthesized using supermolecular aggregates formed by melamine and citric acid as the nitrogen source, via a dry-freezing process, followed with a calcination. Nitrogen doping enhances the interaction between Li 3 VO 4 and carbon, reduces the charge-transfer resistance over the interface, and restrains the pulverization and aggregation upon cycling. The design of porous structure accelerates the permeation of electrolyte and increases the contact between active materials and electrolyte. The synergistic effects between N-doped carbon and porous structure significantly improve the electrochemical performances. Thus, this composite delivers a capacity of 405.1 mAh g−1 at 0.1 A g−1 or 199.9 mAh g−1 at 10.0 A g−1 within 0.2–3.0 V. After 1000 cycles at 4.0 A g−1, the specific capacity is still kept as 236.6 mAh g−1. By pairing with commercial LiCoO 2 , this composite delivers a high energy density of 195.05 Wh kg−1 total at 70.52 W kg−1 total , and 94.06 Wh kg−1 total at 3.9 kW kg−1 total. [ABSTRACT FROM AUTHOR]

Graphical abstract Cu 3 Ge/Ge@C nanocomposites crosslinked by the in situ formed carbon nanotubes (CNTs-Cu 3 Ge/Ge@C) is reported, which exhibits excellent electrochemical performance for Li-ion batteries. Highlights • Cu 3 Ge/Ge@C nanocomposites crosslinked by the in situ formed carbon nanotubes (CNTs-Cu 3 Ge/Ge@C) were fabricated. • The CNTs-Cu 3 Ge/Ge@C nanocomposites structure has obvious good influences on electrochemical performance. • The obtained product exhibited high rate capacity retention in half cell. Abstract In a convenient and uncomplicated way, Cu 3 Ge/Ge@C nanocomposites crosslinked by the in situ formed carbon nanotubes (CNTs-Cu 3 Ge/Ge@C) is reported. In this method, carbon nanotubes are produced in situ to crosslink Cu 3 Ge/Ge@C nanocomposites by the catalysis action of nascent Cu∗ under an acetylene atmosphere at 500 °C, in which the nascent Cu∗ is created by the reaction between CuCl and Ge particles, Cu 3 Ge is then synchronously formed by the Ge and Cu∗. Investigated as the anode materials for lithium ion batteries, a high capacity retention of 1013.4 mA h g−1 is exhibited by the prepared CNTs-Cu 3 Ge/Ge@C at 0.5C after 1000 cycles and a high rate capacity of 931.7 mA h g−1 at 10C in Li-Ge half cells. [ABSTRACT FROM AUTHOR]

Lithium-ion capacitors, as a hybrid electrochemical energy storage device, realize high specific energy and power density within one device, thus attracting extensive attention. Here, hierarchically porous Li 3 VO 4 /C nanocomposite is prepared by a solvo-thermal reaction, followed with a post-annealing process. This composite has macropores at the center and mesopores in the wall, thus effectively promoting electrolyte penetration and structure stability upon cycling simultaneously. Compared to mesoporous Li 3 VO 4 , the enhanced rate capability and specific capacity of hierarchically porous Li 3 VO 4 /C indicate the synergistic effect of mesopores and macropores. Inspired by these results, this composite is coupled with mesoporous carbon (CMK-3) for lithium-ion capacitors, generating a specific energy density of 105 Wh kg −1 at a power density of 188 W kg −1 . Even if the power density increases to 9.3 kW kg −1 , the energy density still remains 62 Wh kg −1 . All these results demonstrate the promising potential of hierarchically porous Li 3 VO 4 in lithium ion capacitors. [ABSTRACT FROM AUTHOR]

In lithium ion batteries anode material is very crucial. Exploring the high-performance anode materials remains a great challenge. Here, Ti 2 Nb 10 O 29 /Ag composite was obtained. Electrochemical measurements demonstrate that Ti 2 Nb 10 O 29 /Ag composite shows good electrochemical performance than pure Ti 2 Nb 10 O 29 , mostly due to enhanced electronic conductivity after Ag-coating. The specific capacities of Ti 2 Nb 10 O 29 /Ag composite can be as high as 253 and 173 mAh g −1 at 1 and 10C, respectively, and the specific capacity is 132 mAh g −1 at 20C. Moreover, the Ti 2 Nb 10 O 29 /Ag composite exhibited excellent cyclic stability, even after 500 cycles, its specific capacity at 10C still stabilized at a large value of 142 mAh g −1 , which was in sharp contrast to the corresponding values of pure Ti 2 Nb 10 O 29 (68 mAh g −1 ). The high electrochemical performance demonstrated that Ti 2 Nb 10 O 29 /Ag composite is highly promising anode materials for Li-ion batteries. [ABSTRACT FROM AUTHOR]

A multiphase Ge-based Ge/FeGe/FeGe 2 /C (Fe-Ge-C) composite is prepared through the reaction between ferrous tartrate and GeO 2 at Ar/H 2 atmosphere, in which the active Ge, alloying components and amorphous carbon are generated synchronically. When evaluated as an anode material for lithium ion batteries, the Fe-Ge-C anode manifests an enhanced capacity of 1095 mA h g −1 at 0.1 A g −1 and with capacity retention of 890 mA h g −1 at 0.5 A g −1 over 400 cycles. A good rate capacity of 465 mA h g −1 at 10 A g −1 is also obtained. The synchronically formed conductive alloying components and amorphous carbon lead to the long cycle stability, and good rate capability. Furthermore, the synthetic route could be extended to the preparation of other kinds of multiphase Ge-based composites. [ABSTRACT FROM AUTHOR]

[Display omitted] • A controlled prelithiated strategy is designed to enhance the ICE of siloxene. • Prelithiated siloxene anodes show high ICE and stable SEI. • The effects of prelithiated condition on physical and electrochemical performance are probed. • Stable 5V full cells is obtained with prelithiated siloxene anodes. Two-dimensional siloxene nanosheet has attracted great attention as an advanced anode for lithium-ion batteries (LIBs) due to its special characters. However, the high surface area leads to a low initial Coulombic efficiency (ICE) and large irreversible capacity, impeding the further application of siloxene. In this work, controlled chemical prelithiation is designed to overcome the issue. The influences of prelithiated conditions on physical and electrochemical performance are researched. Uniform SEI film and high coulombic efficiency is obtained with a 15 min prelithiation process. The prelithiated siloxene anode shows high ICE, superior rate performance and stable cycling performance. When coupled with 5 V-class LiNi 0.5 Mn 1.5 O 4 cathodes, an enhanced capacity retention of 94.3 % is achieved after 200 cycles. This work may be useful for designing advanced anodes for rechargeable batteries. [ABSTRACT FROM AUTHOR]

Uniform MoO 2 nanoparticles were synthesized and evaluated as intercalation-type lithium anode material within the potential window of 1.0–2.5 V. A remarkable high capacity of 226 mA h g −1 at 0.1 C and ultra-long cycle life of 7000 cycles at 5 C with capacity retention of 135 mA h g −1 (96% of initial capacity) have been achieved, which is comparable than that of commercial Li 4 Ti 5 O 12 anode but with higher capacity. Furthermore, a full cell composed of MoO 2 anode and LiCoO 2 cathode was assembled exhibiting a high energy density of 179 Wh kg −1 (based on total mass of cathode and anode active material) and capacity retention of 169 mA h g −1 (87% of initial capacity) after 500 cycles at 1 C. [ABSTRACT FROM AUTHOR]

High capacity electrodes based on Ge composite anode and commercial LiCoO 2 cathode, are evaluated and combined to fabricate a high energy lithium ion battery. The Ge composite anode, Ge/CHNs (Ge/carbon hybrid nanoparticles), is prepared with a co-precipitation followed by pyrolysis process, delivering a capacity of >1000 mA h g −1 over 2000 cycles. While for full cell assembling, galvanostatic cycling in lithium half-cells has been applied for prelithiating Ge/CHNs anodes to eliminate the first cycle irreversible capacity loss. Such process is shown to enable capacity matching between Ge/CHNs anodes and LiCoO 2 cathodes, further influence the working voltage and cycle stability of the full cells. Finally, the lithium ion battery system based on the prelithiated Ge/CHNs anode and LiCoO 2 cathode demonstrates a high energy density of 370 Wh kg −1 after 300 cycles between 2.7 and 4.4 V at 1C (the energy density here is based on the total weight of Ge/CHNs and LiCoO 2 ), with average capacity fading about 0.018% per cycle. Thus, the designed battery system is promising candidate for energy storage applications with demand of high energy density and long cycle life. [ABSTRACT FROM AUTHOR]

Porous TiNb 2 O 7 nanospheres comprised of nanoparticles have been synthesized with the assistance of block copolymer P123 (EO 20 PO 70 EO 20 ). Such porous TiNb 2 O 7 nanospheres, with diameter of 500 nm, exhibit a BET surface area of 23.4 m 2 /g and pore volume of 0.155 cm 3 /g. As the anodes for lithium-ion batteries, the TiNb 2 O 7 nanospheres present a reversible capacity of 160 mA h/g after 10000 cycles at 5 C with a capacity loss of only 0.0033% per cycle, and good rate performance of 167 mA h/g at 50 C. Furthermore, the TiNb 2 O 7 materials still maintain the morphology of nanospheres and the porous structure even after 10000 cycles. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nonflammable ternary all-fluorinated carbonate electrolyte is proposed to construct stable F-rich SEI/Li interface on 3D Li-MXene anode. • Nonflammable electrolyte system can effectively address the safety concerns. • A 3D flexible MXene based lithium metal anode is designed to accommodate the volume changes and enhance the charge transport. Recognized as the most attractive and promising anode, Li metal has been pursued for its high specific capacity and lowest standard potential. However, the hazardous Li dendrite growth is one of the most challenging issues for LMB, which brings about fragile SEI formation, low CE, large volume change and even safety issues. To tackle these problems, we design a 3D flexible MXene based lithium metal anode to accommodate the volume changes, accelerate the charge transport and lower the specific current density. Moreover, nonflammable ternary all-fluorinated carbonate electrolyte system is proposed to construct stable interface by introducing LiF-rich SEI and address the safety concerns. With these synergetic effects, 3D Li-MXene anode in ternary all-fluorinated electrolyte shows significantly improved reversibility with high average CE at 94.5 % after 200 cycles. Full Li metal cell with LFP cathode, composited 3D anode and nonflammable electrolyte delivers high-capacity retention of 95.7 % at 300 mAh g−1 after 200 cycles and excellent rate ability. These results pave a new direction for developing high safety and high-performance Li metal batteries and can also be extended to other rechargeable metal-anode-based batteries such as Na/K/Mg/Ca et al. [ABSTRACT FROM AUTHOR]

Highlights: [•] An acetylene reduction route is designed to synthesis uniformly dispersed Sn-MnO@C nanocomposite. [•] Synchronously formed Sn and MnO nanocrystalline are uniformly dispersed in the amorphous carbon matrix. [•] The composite shows a reversible capacity of 684mA h g−1 after 280 cycles. [•] Fine electrochemical performance attributes to uniformly dispersed nanoparticles, porous structure and carbon matrix coating. [Copyright &y& Elsevier]

Abstract: Carbon-coated α-FeSe nanoparticles in an average size of 200nm have been prepared by a facile one-pot reaction. As an anode material for lithium batteries, the core-shell α-FeSe@C composites showed a discharge plateau at 1.5V, which could effectively avoid the formation of the lithium dendrites and the solid-electrolyte interface layer. They delivered a sustainable reversible capacity of 340mAhg−1 after 40cycles, which is about twice as much as that of the Li4Ti5O12 (175mAhg−1), thereby indicating its promising applications for lithium storage. [Copyright &y& Elsevier]

Abstract: Well dispersed CdCO3/carboxylated carbon nanotubes (CNTs) nanocomposites are synthesized via a facile solution method. As a novel anode material for lithium-ion batteries, the CdCO3/CNTs nanocomposites deliver an initial reversible capacity of 876mAhg−1 and a better cycle ability. The superior electrochemical performance can be attributed to its unique hierarchy architecture, which facilitate the electron transport and accommodate the large volume change during the alloying/de-alloying reactions. [Copyright &y& Elsevier]

Highlights: [•] Graphene-encapsulated Fe2O3 nanorice was fabricated at room temperature. [•] The Fe2O3 nanorice was uniformly wrapped in the graphene sheets. [•] The composite shows higher capacity retention after 500 cycles. [•] The morphology of the Fe2O3 nanorice in the composite was kept after 500 cycles. [Copyright &y& Elsevier]

Abstract: Well dispersed MnCO3/carboxylated carbon nanotube (CNT) nanocomposites are prepared by a facile solution precipitation method. Transmission electron microscopy (TEM) characterizations show that due to heterogeneous nucleation sizes the addition of carboxylated CNT is able to suppress growth of MnCO3 particles, resulting in formation of nano-sized particles. Electrochemical characterization of lithiation/delithiation of the MnCO3/CNT nanocomposites reveals a large capacity of 772mAhg−1 for the first cycle with 84% capacity retention after 100 cycles. The superior electrochemical performance of the MnCO3/CNT nanocomposites electrode compared to the pure MnCO3 electrode can be attributed to super-fine particles and good conductivity due to the presence of CNTs. Their large surface area facilitates fast lithium ion and electron transport and accommodates the big volume change during the conversion reactions. [Copyright &y& Elsevier]

Highlights: [•] Pure cubic and tetragonal CuFe2O4 nanocrystals. [•] C- and t-CuFe2O4 exhibit similar electrode reactions except the first cycle. [•] C-CuFe2O4 shows superior capacity and rate capability. [•] Fe x Cu1−x alloy in the discharged electrode were observed for the first time. [ABSTRACT FROM AUTHOR]

Abstract: Fe3O4/C composites have been prepared by sucrose calcining with Fe3O4 particles obtained from ferrous oxalate decomposition. The scanning electron microscopy (SEM) images show that Fe3O4 nanoparticles (Fe3O4 NPS) with average size of 200nm are embedded in the three-dimensional (3D) carbon-framework. As an anode material for rechargeable lithium-ion batteries, the Fe3O4/C composite delivers a reversible capacity of 773mAhg−1 at a current density of 924mAg−1 after 200 cycles, higher than that of the bare Fe3O4 NPS which only retain a capacity of 350mAhg−1. When the current density rises to 1848mAg−1, Fe3O4/C material still remains 670mAhg−1 even after 400 cycles. The enhanced high-rate performance can be attributed to the 3D carbon-framework, which improves the electric conductivity, relaxes the strain stress and prevents the aggregation of Fe3O4 particles during the charge/discharge process. [Copyright &y& Elsevier]

[Display omitted] • A lithiophilic 3D flexible host is fabricated by depositing an ultrafine Au layer on MXene via sputtering. • The Au layer can significantly suppress the lithium dendrites growth. • MXene can facilitates the ion transfer and alleviate the volume changes. • Flexible 3D MXene@Au@Li anode is obtained with superior performance. Lithium metal is the most attractive and promising anode for next-generation high energy batteries. However, uncontrollable dendrite growth of lithium remains a detrimental safety challenge. To tackle this problem, a 3D flexible MXene@Au host is designed by depositing an ultra-fine and robust Au layer on MXene paper via ion-sputtering. The Au layer acts as lithiophilic nuclear agent to ensure homogeneous lithium deposition and suppress the lithium dendrites growth. The as-prepared flexible 3D MXene@Au@Li anode shows significantly enhanced performance. Full lithium metal cell with LFP cathode delivers high capacity retention of 98.47% even after 200 cycles with good rate capability. These results may be useful for other metallic battery system and has potential applications in sensors, super-capacitor and catalyst etc. [ABSTRACT FROM AUTHOR]

Abstract: ZnCO3 nanoparticle aggregations with porous morphology are prepared via a facile solid-state metathesis reaction in ambient environments. For the first time, ZnCO3 is characterized as a novel anode material for lithium-ion batteries. The porous ZnCO3 delivers an initial reversible capacity of 735mAhg−1 and good rate ability. The good electrochemical performance can be attributed to its unique hierarchy architecture, which facilitates the ion transport and buffers the large volume change during the alloying/de-alloying reactions. [Copyright &y& Elsevier]

Sodium ion batteries (SIB) have wide applications in the field of energy storage due to their low cost. Currently, due to its higher theoretical discharge capacity, tin and tin-based compounds are expected to become SIB anode materials. Here, 2D SnS 2 nanosheets with thickness of about 20 nm loaded on reduced graphene oxide (RGO) material (SnS 2 /RGO) was synthesized by a hydrothermal method, which display superior properties. When the denseness of current is 100 m A/g, the discharge capacity of the first cycle is as high as 956.1 m Ah/g, and the initial Coulombic efficiency is up to 60.0%. From the third cycle to the 200th cycles, the capacity decline rate of each cycle is about 0.13%; after 200 cycles the discharge capacity is still 443.4 m Ah/g. This outstanding performance is ascribed to the composite structure of SnS 2 /RGO, which helps to alleviate the stress of volume change during sodium ion insertion and extraction and enhances the conductivity of the SnS 2 material. Image 1 • SnS 2 electrode material was prepared by hydrothermal method. • The SnS 2 material loaded on RGO to improve the electrochemical performance. • At a current density of 100 mA/g, the initial discharge capacity is as high as 841.4 mAh/g. • After 100 cycles, the high discharge capacity of 471.1 mAh/g was still obtained. [ABSTRACT FROM AUTHOR]

• Phosphorus-doped mesoporous carbon was successfully synthesized from waste tires. • Phosphorus-doped mesoporous carbon was used as anode materials for KIBs. • The doped mesoporous carbon showed a capacity of 128.5 mA h/g at 500 mA/g. Recycling of waste tires is an important technology due to the health and environmental problems caused by them. Herein, we developed a low-cost method to prepare phosphorus-doped mesoporous carbon (PMC) by a preferred phosphoric acid treatment and high temperature calcination process of waste tires. After doping with phosphorus, the PMC electrode exhibited improved reversible capacity (181.8 mA h/g @ 100 mA/g) and good rate performance. It still delivers a specific capacity of 128.5 mA h/g when cycled under 500 mA/g. The increased performance of PMC was owing to the joint effect of phosphorus doping and mesoporous structure, which could shorten the transport path of K+ and improve the electrochemical reactivity for potassium batteries. [ABSTRACT FROM AUTHOR]