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Reasonable design of cathode-electrolyte interface (CEI) with high electrochemical stability and high ionic conductivity is crucial for improving the electrochemical performance of cathode materials. Herein, lithium difluoro(oxalate)borate (LiDFOB) is used as an efficient electrolyte additive to form a robust, dense, and conductive CEI on LiFePO4 cathode, which significantly enhances the rate capability and cycling stability. Specifically, the introduction of LiDFOB promotes the formation of a fluoride (F)- and boron (B)-rich CEI, effectively enhancing ion transport kinetics. Simultaneously, the generated CEI exhibits excellent stability, efficiently suppressing the continuous decomposition of the electrolyte and structural damage of LiFePO4 cathode over prolonged cycling. Consequently, the LiFePO4 cathode with LiDFOB additive exhibits a highly reversible capacity of 133.4 mAh g−1 at 0.5 C and an excellent capacity retention of 94.4% over 400 cycles, which is superior to LiFePO4 without additive (only 66.1% capacity retention). This work confirms the promising potential of LiDFOB as a multifunctional electrolyte additive and provides new insights for constructing high-performance CEI. [ABSTRACT FROM AUTHOR]

While the reaction activity of Li3VO4 could be improved by a reduction in particle size, the enhanced surface defects will degrade the cyclability. It is very challenging to achieve the best balance between high-rate performance and long lifespan. Herein we designed a novel architecture of crystallized Li3VO4 nanoparticles embedded in carbon nanoflakes (mc-LVO/C NFs) through an improved electrostatic spray method. The as-prepared mc-LVO/C NFs exhibit comprehensive high capacity and long-life performance at high-rate, with the integral 2D morphology and the specific LVO embedded architecture promoting fast reaction kinetics, and the crystallized LVO rendering high and stable reactivity. It delivers a high capacity of 610 mA h g−1 at 0.5 A g−1, without obvious capacity delay over 500 cycles. After 7 periods from 0.2 to 10 A g−1 over 570 cycles, a high capacity of 790 mA h g−1 could be restored when reverting the current density to 0.2 A g−1. Even cycling at a high discharge/charge current of 10/8 A g−1, the mc-LVO/C NFs could deliver stable cycling over 10 000 cycles, delivering high capacity of 204 mA h g−1. Combining the advantages of high reactivity and the high stability of LVO in an electrode may be referential for the design of advanced LVO-based electrodes. [ABSTRACT FROM AUTHOR]

Lithium vanadium oxide (Li3VO4) is a highly promising anode material for lithium-ion batteries due to its high theoretical capacity and moderate operation voltage. However, its low intrinsic electronic conductivity leads to an undesirable rate capability and restricts its practical applications. To address this issue, we designed a structure of hierarchical porous carbon network-wrapped Li3VO4 nanoparticles to enhance the overall electrochemical performance, especially at high rates. Polyacrylonitrile (PAN) and poly-(methyl methacrylate) (PMMA) were employed as carbon sources and porous templates during the electrospinning and subsequent calcination processes. This approach can enhance the electronic conductivity, improve the contact area between Li3VO4 and the electrolyte, and decrease the ion/electron diffusion path. As a result, the constructed hierarchical porous N-doped C nanofiber-encapsulated Li3VO4 nanoparticles (P-LVO/NC NFs) exhibited an ultrahigh discharge capacity of 1039.5 mA h g–1 and a stable capacity of 736.8 mA h g–1 after 500 cycles at 0.5 A g–1. Furthermore, they demonstrated an outstanding rate capability of 397.7 mA h g–1 and at 5.0 A g–1. The unique hierarchical porous structure provided excellent reaction kinetics, resulting in exceptional Li-ion storage performance. Therefore, the fabricated P-LVO/NC NFs hold great potential as high-performance anode materials. [ABSTRACT FROM AUTHOR]

The rational design of a solid electrolyte interphase (SEI) with high ionic conductivity and high electrochemical stability is significantly important in improving the electrochemical performance of anode materials. Herein, lithium difluoro(oxalate)borate (LiDFOB) is used as an electrolyte additive to generate protective SEI films on Li3VO4 (LVO) anodes. The addition of LiDFOB is beneficial to form a dense, uniform, stable and LiF-richer SEI, which is helpful to boost the Li-ion storage kinetics. In addition, the generated SEI can inhibit the further decomposition of electrolytes and maintain the morphology of LVO anodes during charge/discharge processes. As a result, LVO-based anodes exhibit a much higher capacity (769.5 mA h g−1 at 0.5 A g−1), enhanced rate performance (243.3 mA h g−1 at 5.0 A g−1) and excellent long-term cycling stability (209.9 mA h g−1 after 5000 cycles) when cycled in 1 wt% LiDFOB addition electrolyte. This work confirms that LiDFOB is a promising multi-functional additive for LiPF6 electrolytes and provides new insights into SEI construction towards high-performance LVO anodes. [ABSTRACT FROM AUTHOR]

Li3VO4 is a promising anode material for use in lithium‐ion batteries, however, the conventional synthesis methods for Li3VO4 anodes involve the separate use of lithium and carbon sources, resulting in inefficient contact and low crystalline quality. Herein, lithium polyacrylate (LiPAA) was utilized as a dual‐functional source and an in‐situ polymerization followed by a spray‐drying method was employed to synthesize Li3VO4. LiPAA serves a dual purpose, acting as both a lithium source to improve the crystal process and a carbon source to confine the particle size within a desired volume during high‐temperature treatment. Additionally, the in‐situ synthesis of a porous carbon decorating skeleton prevents the growth and agglomeration of Li3VO4 particles and provides abundant ion/electron diffusion channels and contact areas. Based on the synthesis route and the constructed primary‐secondary structure, the Li3VO4 anodes obtained in this study exhibit an impressive capacity of 596.2 mAh g−1. Moreover, they demonstrate enhanced rate performance over 600 cycles during 10 periods of rate testing, as well as a remarkably long lifespan of 5000 cycles at high currents. The utilization of LiPAA as a dual‐functional source represents a broad approach that holds great potential for future research on high‐performance electrodes requiring both lithium and carbon sources. [ABSTRACT FROM AUTHOR]

The development of lithium-ion batteries (LIBs) is still facing challenges due to the design and optimization of anode materials and their Li-ion storage mechanisms. In this study, we aimed to address this issue by constructing three-dimensional hierarchical heterojunction structures using a double needle electrospinning strategy. The heterostructure was composed of insertion-type Li3VO4 and conversion/alloying-type Ga2O3 embedded porous carbon nanofibers (Li3VO4–Ga2O3@PCNF). The designed heterostructured Ga2O3 and Li3VO4 materials were found to effectively enhance charge transfer dynamics, thereby improving capacity and rate capability. Additionally, the facilitated efficient contact between the electrode and electrolyte, enabling the diffusion of ions and electrons. When applied as an anode material in LIBs, the Li3VO4–Ga2O3@PCNF composite achieved a high capacity of 630.0 mA h g−1 at 0.5 A g−1, and full capacity recovery after 6 periods of rate testing over 480 cycles. When simulating the practical application under a high discharge current of 6.0 A g−1, the Li3VO4–Ga2O3@PCNF could still deliver a high discharge capacity of 322.0 mA h g−1 after 2000 cycles. Furthermore, the composite exhibited a remarkable capacity retention of 77.2% after 2000 cycles at 6.0 A g−1. This research provides valuable guidance for the design of high-performance Li3VO4-based anodes, particularly in addressing the issue of inferior electronic conductivity. [ABSTRACT FROM AUTHOR]