Liu Lei, Li Yong, Su Tao, Li Chao, Hao Zhimeng, Yang Gaojing, Ma Jianmin
School of Chemistry, Tiangong University, Tianjin, 300387, China.
State Key Laboratory of Space Power-Sources Technology, Shanghai Institute of Space Power Sources, Shanghai, 200245, China.
Adv Mater. 2025 Jul 2:e2508595. doi: 10.1002/adma.202508595.
All-climate lithium metal batteries are highly needed, but remains a huge challenge in cycling life due to the existence of unstable electrode electrolyte interphases, especially with nickel-rich layered oxide cathode at high cut-off voltage. To address this question, a functional and robust sandwich-model cathode electrolyte interphase (CEI) is proposed, derived from a LiBF-based electrolyte modified with para-fluorobenzeneacetonitrile (P-FBCN) additive, to realize the stability of 4.8 V Li||LiNiCoMnO (NCM94) battery operated from -60 to 60 °C. The LiF-rich sandwich-model CEI features an outer layer of LiBO-rich to enhance mechanical/thermal stability, and the inner -C≡N-rich anchoring layer to facilitate Li⁺ conduction and inhibit the dissolution of transition metal ions. Notably, the 7.6 Ah-grade Li||NCM94 pouch cell with such electrolyte can yield a high energy density of 544 Wh kg with a long lifespan of 158 cycles.
全气候锂金属电池需求迫切，但由于存在不稳定的电极电解质界面，尤其是在高截止电压下使用富镍层状氧化物阴极时，其循环寿命仍然是一个巨大的挑战。为了解决这个问题，人们提出了一种功能性且坚固的三明治结构阴极电解质界面（CEI），它由添加了对氟苯乙腈（P-FBCN）的基于LiBF的电解质衍生而来，以实现4.8 V Li||LiNiCoMnO（NCM94）电池在-60至60°C温度范围内运行的稳定性。富含LiF的三明治结构CEI具有外层富含LiBO以增强机械/热稳定性，以及内层富含-C≡N的锚固层以促进Li⁺传导并抑制过渡金属离子的溶解。值得注意的是，采用这种电解质的7.6 Ah级Li||NCM94软包电池可实现544 Wh kg的高能量密度以及158次循环的长寿命。
