Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, USA.
Nat Commun. 2013;4:1513. doi: 10.1038/ncomms2518.
Long-life and safe lithium-ion batteries have been long pursued to enable electrification of the transportation system and for grid applications. However, the poor safety characteristics of lithium-ion batteries have been the major bottleneck for the widespread deployment of this promising technology. Here, we report a novel nonaqueous Li(2)B(12)F(12-x)H(x) electrolyte, using lithium difluoro(oxalato)borate as an electrolyte additive, that has superior performance to the conventional LiPF(6)-based electrolyte with regard to cycle life and safety, including tolerance to both overcharge and thermal abuse. Cells tested with the Li(2)B(12)F(9)H(3)-based electrolyte maintained about 70% initial capacity when cycled at 55 °C for 1,200 cycles, and the intrinsic overcharge protection mechanism was active up to 450 overcharge abuse cycles. Results from in situ high-energy X-ray diffraction showed that the thermal decomposition of the delithiated Li(1-x)Ni(1/3)Mn(1/3)Co(1/3)O(2) cathode was delayed by about 20 °C when using the Li(2)B(12)F(12)-based electrolyte.
为了实现交通系统的电气化和电网应用，人们一直在追求长寿命和安全的锂离子电池。然而，锂离子电池较差的安全性能一直是这项有前途的技术广泛部署的主要瓶颈。在这里，我们报告了一种新型的非水合 Li(2)B(12)F(12-x)H(x)电解质，使用双氟(草酸)硼酸锂作为电解质添加剂，与传统的基于 LiPF(6)的电解质相比，在循环寿命和安全性方面具有优异的性能，包括对过充和热滥用的耐受性。用 Li(2)B(12)F(9)H(3)基电解质测试的电池在 55°C 下循环 1200 次时，初始容量保持在 70%左右，并且过充保护机制的固有活性高达 450 次过充滥用循环。原位高能 X 射线衍射结果表明，当使用 Li(2)B(12)F(12)基电解质时，脱锂 Li(1-x)Ni(1/3)Mn(1/3)Co(1/3)O(2)正极的热分解延迟了约 20°C。
