Zhang Miaomiao, Pei Cunyuan, Xiang Qiqi, Liu Lintao, Dai Zhongxu, Ma Huijuan, Ni Shibing
College of Materials and Chemical Engineering, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, China Three Gorges University, Yichang, 443002, China.
Hubei Three Gorges Laboratory, Yichang, 443007, China.
Phys Chem Chem Phys. 2024 Jan 3;26(2):1148-1155. doi: 10.1039/d3cp04952c.
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 LiVO (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 at 0.5 A g), enhanced rate performance (243.3 mA h g at 5.0 A g) and excellent long-term cycling stability (209.9 mA h g after 5000 cycles) when cycled in 1 wt% LiDFOB addition electrolyte. This work confirms that LiDFOB is a promising multi-functional additive for LiPF electrolytes and provides new insights into SEI construction towards high-performance LVO anodes.
设计具有高离子电导率和高电化学稳定性的固体电解质界面（SEI）对于提高负极材料的电化学性能具有重要意义。在此，二氟草酸硼酸锂（LiDFOB）用作电解质添加剂，在LiVO（LVO）负极上生成保护性SEI膜。添加LiDFOB有利于形成致密、均匀、稳定且富含LiF的SEI，这有助于提升锂离子存储动力学。此外，生成的SEI可抑制电解质的进一步分解，并在充放电过程中保持LVO负极的形态。结果，在添加1 wt% LiDFOB的电解质中循环时，基于LVO的负极表现出更高的容量（0.5 A g时为769.5 mA h g）、增强的倍率性能（5.0 A g时为243.3 mA h g）以及优异的长期循环稳定性（5000次循环后为209.9 mA h g）。这项工作证实LiDFOB是一种有前景的用于LiPF电解质的多功能添加剂，并为高性能LVO负极的SEI构建提供了新的见解。
