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Typically, the practical lithium-ion capacitor (LIC) is composed of a capacitive cathode (activated carbon, AC) and a battery-type anode (graphite, soft carbon, hard carbon). There is a risk of the LIC cell overcharging to an unsafe voltage under electrical abuse conditions. Since the anode potential is usually quite low during the charging process and can be controlled by adjusting the amount of anode materials, the overcharge performances of LIC full-cell mainly depend on the AC cathode. Thus, it is necessary to independently investigate the overcharge behaviors of the AC cathode in nonaqueous Li-ion electrolytes without the interference of the anode electrode. In this work, the stable upper potential limits of the AC electrode in three types of lithium-ion electrolytes were determined to be 4.0−4.1 V via the energy efficiency method. Then, the AC//Li half-cells were charged to 5.0 V and 10.0 V, respectively, to investigate the overcharge behaviors. For the half-cells with propylene carbonate (PC)-based electrolytes, the voltage increased sharply to 10.0 V with a vertical straight line at the end of the overcharging process, indicating that the deposits of electrolyte decomposition had separated the AC electrode surface from the electrolytes, forming a self-protective passivation film with a dielectric capacitor behavior. The dense and compact passivation film is significant in separating the AC electrode surface from the electrolytes and preventing LIC cells from volume expansion and explosion risks under electrical abuse and overcharging conditions. [ABSTRACT FROM AUTHOR]

SiOx is one of the most promising anode materials for lithium-ion batteries (LIBs), due to its high theoretical capacity and low cost. However, the huge volume expansion and low electron/ion diffusion rate hinder its further commercial applications. Herein, a simple molecular polymerization method is developed to synthesize N,P co-doped SiOx–C composites (denoted as SiOx–C@CNT), in which SiOx and carbon are uniformly dispersed at the atomic level, and the embedded carbon nanotubes improve the lithium ion diffusion kinetics. Benefiting from the unique structure, the SiOx–C@CNT composites exhibit a high reversible capacity of 848 mA h g−1 at 0.1 A g−1 and long cycling stability (84.0% capacity retention after 1500 cycles). More impressively, the LiCoO2∥SiOx–C@CNT full battery also exhibits stable cycle life (only 4.7% capacity loss after 300 cycles at 1 C). These results show the application potential of the SiOx–C@CNT anode in LIBs. [ABSTRACT FROM AUTHOR]

With the enormous development of the electric vehicle market, fast charging battery technology is highly required. However, the slow kinetics and lithium plating under fast charging condition of traditional graphite anode hinder the fast charging capability of lithium‐ion batteries. To develop anode materials with rapid Li‐ions diffusion capability and fast reaction kinetics has received widely attentions. This review summarizes the current status in the exploration of fast charging anode materials, mainly including the critical challenge of achieving fast charging capability, the inherent structures and lithium storage mechanisms of various anode materials, as well as the recent progress to improve the rate performance involving morphology regulation, structure design, surface/interface modification, as well as forming multiphase systems. Finally, the challenges and future directions of developing fast charging Li‐ion batteries are highlighted. [ABSTRACT FROM AUTHOR]

As anode materials for high‐performance sodium‐ion batteries and potassium‐ion batteries, bimetallic selenides have attracted great concern due to their relatively high electrical conductivity and electrochemical activity. However, the formidable challenge in the reaction process is the large volume change, leading to the structural collapse of material, and eventually the decline in electrochemical performance. Herein, a composite of hierarchical CoSe2–MoSe2 tubes anchored on reduced graphene oxide nanosheets (CoSe2–MoSe2/rGO) is designed by an in situ hydrothermal selenization treatment. Benefiting from the synergistic effects between CoSe2 and MoSe2, unique hierarchical structure, and effective reduced graphene oxide coating, the CoSe2–MoSe2/rGO exhibited improved reaction kinetics and structural stability, and thus good electrochemical properties. A combination mechanism of intercalation and conversion of CoSe2–MoSe2/rGO by forming NaxCoSe2 and Mo15Se19 as intermediate states is put forward on the basis of in situ and ex situ XRD analyses. [ABSTRACT FROM AUTHOR]

As an energy‐storage system, rechargeable potassium‐ion batteries (PIBs) have aroused widespread attention in recent years due to their earth abundance, low standard redox potential, and high ionic conductivity. The development of high‐performance electrode materials is key to optimize the battery performance and useful to improve the feasibility of PIB technology. In this sense, a minireview on alloying‐type anode materials for advanced PIBs is provided, covering the potassium storage properties, reaction mechanisms, theoretical analysis, electrochemical performance, and suitable binders and electrolytes. [ABSTRACT FROM AUTHOR]

The sluggish kinetics of battery-type anode limits the realization of high capacitance especially at elevated charge-discharge rates for lithium-ion capacitors (LICs). In this work, graphene wrapped carbon cages (G x P y) are obtained via a facile physical-confined pyrolysis approach from graphene oxide (GO)/polyvinylidene fluoride (PVDF), which exhibits great promise as a fast and large-capacity anode for LICs. The thermal degradation process analysis reveals that carbon cages with abundant mesopores derived from the dehalogenation of PVDF are formed spontaneously due to the HF releasing in the pyrolysis process with the aid of physical confined GO template. Hollow carbon cages could ameliorate the Li+ transport path, while 2D graphene serves as a conducting bridge connecting the isolated carbon cages to minimize the barrier of charge transfer. As a result, a LIC pouch-cell based on G x P y hierarchical carbon anode demonstrates high energy density and superior power density, as well as remarkable cycle life. This study may open a unique avenue for designing fast and large-capacity carbon anode and push the development of high-performance LICs. We report a physical-confined pyrolysis pathway to prepare hierarchical carbon anode composed of graphene wrapped carbon cages. Carbon cage structure can ameliorate the Li+ transport path, while graphene serves as a conducting bridge connecting the isolated carbon cages, resulting fast kinetics and large capacity as anode material. As a result, a LIC pouch-cell based on G x P y hierarchical carbon anode demonstrates impressive electrochemical performance. [Display omitted] • A physical-confined pyrolysis pathway is developed to prepare hierarchical carbon anode composed of graphene wrapped carbon cages. • The thermal degradation mechanism reveals that carbon cages are derived from the dehalogenation of PVDF due to the HF releasing in the pyrolysis process. • Cage structure can ameliorate Li + transport path, resulting fast kinetics and large capacity as anode material. [ABSTRACT FROM AUTHOR]

Novel layered Li3V2(PO4)3/rGO&C sheets are synthesized by novel interfacial modified assembly, freeze-drying and confined annealing processes. The uniform LVP layers are alternated with rGO&C layers to form the composite layered structure, providing effective electron and ion transport. As a lithium-ion battery cathode, the composite displays excellent electrochemical performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • The layered bimetal sulfides composites provide large diffusion channels for Na+. • The wrapping of rGO increases conductivity and ensures the structural stability. • The rod-like composite exhibits excellent electrochemical properties. Substantial researches have been devoted to metal sulfides for developing anode materials of sodium ion batteries on account of the high theoretical capacity and high reaction activity. Nevertheless, the issue of volumetric variation impedes their development. Herein, a composite of cobalt-molybdenum binary metal sulfide wrapped by reduced graphene oxide (CoS 2 -MoS 2 @rGO) was synthesized by an annealing process and rGO wrapping using CoMoO 4 as the precursor. The as-prepared CoS 2 -MoS 2 @rGO composite exhibits good cycling performance with 561.5 mA h g−1 at the 50th cycle at the current density of 0.2 A g−1 and rate capability of 382.2 mA h g−1 at 2 A g−1 for sodium ion batteries, which is attributed to the uniform coating of rGO to buffer the volumetric variation and maintain the structural integrity accompanied with improved ion diffusion and enhanced electrical conductivity. [ABSTRACT FROM AUTHOR]

The application of Sn-based materials and transition metal oxides (TMOs) with high theoretical capacities as anodes for lithium ion batteries is severely limited for the low cycle lifespan due to huge volume changes. Combining the Sn-based or TMO materials with one-dimensional (1D) carbon nanofibers as a lithium storage anode is one of the effective means to improve the cycle stability, rate performance, initial coulombic efficiency and electrical conductivity of lithium ion batteries. In this work, a novel Sn particles coated composite of SnO x /ZnO and N-doped carbon nanofibers (Sn/SnO x /ZnO@N-CNFs) with high reversibility and long-life lithium storage boosted by pseudocapacitance behavior was fabricated using a simple electrospinning technique and subsequent calcining process. The high theoretical capacity of SnO 2 , high Li ion diffusion coefficient of ZnO, as well as stable cycle performance and great conductivity of N-CNFs were integrated into the composite by the synergistic effect, which delivers a high reversible capacity of 588.7 mAh/g after 100 cycles at a current density of 0.5 A/g. More importantly, in the case of great rate performance and cycle stability at high current density, the Sn/SnO x /ZnO@N-CNFs electrode is endowed with significantly improved initial coulombic efficiency and prominent advantage in electrical conductivity. The comprehensive performance, facile material fabrication method and enhanced pseudocapacitive lithium storage for Sn particles coated SnO x /ZnO and N-doped carbon nanofibers hybrid could contribute to the practical application of the updated energy storage devices. Sn coated SnO x /ZnO@N-CNF composites were fabricated by electrospinning technique and subsequent calcining process. The Sn/SnO x /ZnO-1@N-CNF electrode shows remarkable rate performance, great cycle stability, improved initial coulombic efficiency, boosted electrical conductivity and enhanced pseudocapacitive lithium storage in advanced lithium-ion batteries. Image 1 • The Sn coated SnO x /ZnO@N-CNF composites was fabricated using a facile electrospinning technique and subsequent calcining process. • The Sn/SnO x /ZnO@N-CNF electrode deliver a high reversible capacity of 588.7 mAh/g after 100 cycles at the current density of 0.5 A/g, with excellent rate performance, great electrical conductivity and high coulombic efficiency. • The high reversibility and long-life lithium storage of the Sn/SnO x /ZnO@N-CNF electrode is boosted by pseudocapacitance behavior. [ABSTRACT FROM AUTHOR]

Sub-valent silicon oxide (SiO x) is a promising next-generation anode material in lithium-ion batteries. However, SiO x still suffers large volume expansion during the lithiation, resulting in deteriorated battery performance. Herein, we report a low-cost and easy-to-scale-up method to prepare a SiO x -based anode (named as SiO x @G-Ni) by drop-casting the slurry of asphalt, micron-sized SiO x powder, nickel salt and carbon nanotubes onto a Cu foil and subsequent thermal pyrolysis. The obtained electrode consists of a rigid graphenic carbon network that is embedded with micron-sized SiO x , nickel nanoparticles and carbon nanotubes. The SiO x @G-Ni electrode delivers a specific charge capacity of 1061 mA h g −1 at 0.08 A g−1, and a capacity retention rate of 86.7 % after cycled 500 times at 1.6 A g−1. The full battery SiO x @G-Ni||LiCoO 2 reaches a capacity retention rate of 79.3 % after 250 cycles at 0.5 C. The method employed in this work could be used for the preparation of the SiO x -based anode for high-performance lithium-ion batteries. • Preparation of binder-free micron-sized SiO x electrodes by drop-casting method. • Utilize the catalytic effect of nickel particles to form a multilayer graphenic network. • The SiOx@G-Ni electrode delivers great half-cell and full-cell cycle performance. [ABSTRACT FROM AUTHOR]