Search

While the intrinsic safety and capacity merits of Li3VO4 endow it with great promise in LIBs, the moderate lifespan under a high rate hinders its practical application. Herein, we demonstrate for the first time, the boosting of an unprecedented high-rate performance of the Li3VO4-based electrode via a novel honeycomb architecture design and its electrochemical reconstruction upon cycling. Li3VO4/C honeycombs (LVO/C Hs) consisting of primary carbon-coated Li3VO4 nanoparticles have been constructed by a self-assembly strategy, through a developed electrospraying approach using polyvinyl alcohol as a morphology regulator. In the LVO/C Hs, the local LVO@C nanoparticle constituents render high activity, and the integral honeycomb-like architecture facilitates electron transfer and promotes a synergistic effect between the constituents. The lithiation-driven electrochemical reconstruction in cycling ensures the integrity of the honeycomb structure, and at the same time, the LVO nanoparticles are refined to 3–5 nm, producing abundant nanopores. The self-reconfigured structures with ultrasmall nanoparticles and large void space effectively shorten the ion diffusion pathway. The above structural characteristics trigger a continuous high capacitive charge storage, giving rise to unprecedented high-rate performance. The LVO/C Hs electrode delivered a discharge capacity recovery of 590.0 mA h g−1 at 0.5 A g−1 after 6 periodic rate performance tests from 0.5 to 10 A g−1 over 430 cycles. When cycling at a high discharge current of 6 A g−1, the LVO/C Hs electrode could maintain stable cycling over 14 000 cycles with a high discharge capacity of 324.5 mA h g−1. The lifespan of the LVO/C Hs is the longest among all the reported LVO-based electrodes, demonstrating great potential in long-life and high-rate applications such as electric vehicles and power stations. [ABSTRACT FROM AUTHOR]

The high-rate Li-ion storage of Li3VO4-based electrodes has been hindered by unsatisfactory reaction kinetics caused by specific challenge in morphology and structure regulation. Self-supported Li3VO4/N doped C fibers (SS LVO/NC NFs) with foldability and the specific architecture of LVO nanoparticles embedded homogeneously in interlaced NC fibers are designed for the first time via a modified electrospinning approach. The morphological merits of the LVO/NC NFs and the structural merits of the integral electrode are well integrated in the SS LVO/NC NFs, resulting in continuously excellent reaction kinetics and superb high-rate performance. After 850 cycles of repeated rate performance testing from 0.5 to 5 A g−1, the discharge capacity could restore to 592.3 mA h g−1 when directly reverting the current back to 0.5 A g−1. When gradually reducing the current from 5 to 0.5 A g−1, the SS LVO/NC NFs could deliver a high discharge capacity of 553.2 mA h g−1 after repeated rate performance testing from 5 to 0.5 A g−1 over 820 cycles. When simulating the practical application under a high charge/discharge current of 4/6 A g−1, the SS LVO/NC NFs could still deliver a high discharge capacity of 230.4 mA h g−1 after 8000 cycles. The excellent performance and the foldability of the SS LVO/NC NFs endow it with potential application in wearable devices. [ABSTRACT FROM AUTHOR]

Na3VO4 (NVO) nanoparticles were synthesized first by us as a creative anode material for lithium-ion batteries (LIBs). For the purpose of fully demonstrating the potential of NVO for lithium storage, herein, we introduce inexpensive, pollution-free, and scalable biomass carbon to regulate the morphology of NVO, constructing a hybrid of NVO nanoparticles anchored on honeycomb carbon networks (NVO NPs/HCNs). Employed as LIB anodes, NVO NPs/HCNs deliver far superior comprehensive electrochemical properties than those of pure NVO nanoparticles. This is attributed to interconnected carbon networks for improving electrical conductivity and a smaller particle size for reducing the Li+ transfer distance, thus achieving fast reaction kinetics. In addition, the constructed Li-ion full cell with a NVO anode and Li3V2(PO4)3 cathode both using honeycomb carbon networks as the substrate also shows excellent lithium storage properties, opening an avenue to design advanced materials for innovative energy storage technologies. [ABSTRACT FROM AUTHOR]

The high-rate performance of Ga2O3-based electrode has been seriously restricted by its modest reaction kinetics caused by the particular challenge of morphology regulation. Herein, Ga2O3–Li3VO4/N-doped C nanofibers (G–LVO/NC NFs) were successfully designed and firstly prepared via a concise electrospinning approach. The as-prepared G–LVO/NC NFs exhibit self-adaptive reaction kinetics owing to the synergistic effect among Ga2O3, Li3VO4, and N-doped C, resulting in superb high-rate Li-ion storage. After repeated rate-performance testing (4 periods) from 0.2 to 10.0 A g−1 over 380 cycles, a high reversible capacity of 968.8 mA h g−1 could be restored when reverting the current back to 0.2 A g−1. When cycling at various high charge/discharge currents of 2.0/4.0, 4.0/6.0, 6.0/8.0, and 8.0/10.0 A g−1, the G–LVO/NC NFs also deliver outstanding cyclability and high charge/discharge capacity of 606.5/608.6, 457.6/457.2, 435.6/435.8, and 317.1/317.9 mA h g−1 after 2000 cycles, respectively, demonstrating great potential toward high power density application. [ABSTRACT FROM AUTHOR]

Li3VO4/C nanofibers (LVO/C NFs) with tunable morphology and microstructure are prepared via an aqueous-based electrospinning approach. LVO/C NFs with smooth surface and high defects in C (LVO/C NFs-1) are obtained by pre-annealing in air, while pre-annealing in N2 leads to the formation of LVO/C NFs with numerous nanoparticles embedded in fiber matrix (LVO/C NFs-2). The LVO/C NFs-1 delivers discharge capacity 478.9 mAh g−1 after 100 cycles at 0.2 A g−1 and 307.7 mAh g−1 after 600 cycles at 2.0 A g−1. After 3 periodic rate performance testing from 0.2 to 4.0 A g−1 over 250 cycles, the LVO/C NFs-1 retains high discharge capacity of 444.9 mAh g−1 when reverting the current to 0.2 A g−1. The performance of the LVO/C NFs-1 is distinctly improved compared with that of the LVO/C NFs-2, owing to improved reaction kinetics and continuously high capacitive charge storage. The specific aqueous-based approach for the preparation of LVO/C NFs and the morphology and microstructure-related electrochemical performance may be referential for the design of high-performance Li3VO4-based electrode. [ABSTRACT FROM AUTHOR]

Ga2O3 is a promising anode material for lithium ion batteries (LIBs) owing to its high theoretical capacity and low lithiation potential. However, its performance improvement has been seriously hindered by the sluggish reaction kinetics. Herein, Ga2O3/N doped C nanopapers (Ga2O3/NC NPs) are firstly designed and synthesized via a scalable biomass‐aided approach. The as‐prepared Ga2O3/NC NPs deliver high reversible capacity and prominent rate capability as anode for LIBs, owing to its excellent reaction kinetics. It shows high discharge capacity of 477 mAh g−1 after 200 cycles at 0.2 A g−1, without obvious capacity attenuation upon cycling. After 3 periodic rate performance testing ranging from 0.1 to 1.6 A g−1, the reversible capacity of the Ga2O3/NC NPs still retains to 517 mAh g−1 when the current is reverting to 0.1 A g−1. The low and safe working potential, the prominent electrochemical performance and the scalable synthesis method for the Ga2O3/NC NPs endow it with great promising toward practical application. [ABSTRACT FROM AUTHOR]