He Xiaoya, Hao Wei, Shi Zidan, Tan Yihong, Yue Xinyang, Xie Yujun, Yan Xuzhou, Liang Zheng
Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China.
Global Institute of Future Technology, Shanghai Jiao Tong University, Shanghai 200240, P. R. China.
ACS Nano. 2024 Aug 20;18(33):22560-22571. doi: 10.1021/acsnano.4c08349. Epub 2024 Aug 7.
Lithium metal batteries (LMBs) with LiNiCoMnO (NCM811) cathodes have garnered significant interest as next-generation energy storage devices due to their high energy density. However, the instability of their electrode/electrolyte interfaces in regular carbonate electrolytes (RCEs) results in a rapid capacity decay. To address this, a colloid electrolyte consisting of LiP nanoparticles uniformly dispersed in the RCE is developed by a one-step synthesis. This design concurrently creates stable cathode electrolyte interphase (CEI) and solid electrolyte interphase (SEI) on both electrode surfaces. The cathode interface derived from this colloid electrolyte significantly facilitates the decomposition of Li salts (LiPF and LiDFOB) on the cathode surface by weakening the P-F and B-F bonds. This in situ formed P/LiF-rich CEI effectively protects the NCM811 cathode from side reactions. Furthermore, the LiP embedded in the SEI optimizes and homogenizes the Li-ion transport, enabling dendrite-free Li deposition. Compared to the RCE, the designed colloid electrolyte enables robust cathode and anode interfaces in NCM811||Li full cells, minimizing gas and dendrite formation, and delivering a superior capacity retention of 82% over 120 cycles at a 4.7 V cutoff voltage. This approach offers different insights into electrolyte regulation and explores alternative electrolyte shapes and formulations.
具有LiNiCoMnO（NCM811）阴极的锂金属电池（LMBs）因其高能量密度而作为下一代储能装置引起了广泛关注。然而，其在常规碳酸盐电解质（RCEs）中的电极/电解质界面的不稳定性导致容量迅速衰减。为了解决这一问题，通过一步合成法制备了一种由均匀分散在RCE中的LiP纳米颗粒组成的胶体电解质。这种设计同时在两个电极表面形成了稳定的阴极电解质界面（CEI）和固体电解质界面（SEI）。这种胶体电解质衍生的阴极界面通过削弱P-F和B-F键，显著促进了阴极表面锂盐（LiPF和LiDFOB）的分解。这种原位形成的富含P/LiF的CEI有效地保护NCM811阴极免受副反应的影响。此外，嵌入SEI中的LiP优化并均匀化了锂离子传输，实现了无枝晶锂沉积。与RCE相比，所设计的胶体电解质在NCM811||Li全电池中实现了稳健的阴极和阳极界面，最大限度地减少了气体和枝晶的形成，并在4.7 V截止电压下120次循环中提供了82%的优异容量保持率。这种方法为电解质调控提供了不同的见解，并探索了替代的电解质形状和配方。
