Li Shuai, Yang Shi-Jie, Liu Gui-Xian, Hu Jiang-Kui, Liao Yu-Long, Wang Xi-Long, Wen Rui, Yuan Hong, Huang Jia-Qi, Zhang Qiang
Advanced Research Institute of Multidisciplinary Science, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing, 100081, China.
Key Laboratory of Molecular Nanostructure and Nanotechnology, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
Adv Mater. 2024 Jan;36(3):e2307768. doi: 10.1002/adma.202307768. Epub 2023 Nov 30.
All-solid-state lithium (Li) metal batteries (ASSLMBs) employing sulfide solid electrolytes have attracted increasing attention owing to superior safety and high energy density. However, the instability of sulfide electrolytes against Li metal induces the formation of two types of incompetent interphases, solid electrolyte interphase (SEI) and mixed conducting interphase (MCI), which significantly blocks rapid Li-ion transport and induces uneven Li deposition and continuous interface degradation. In this contribution, a dynamically stable mixed conducting interphase (S-MCI) is proposed by in situ stress self-limiting reaction to achieve the compatibility of Li metal with composite sulfide electrolytes (Li PS Cl (LPSCl) and Li GeP S (LGPS)). The rational design of composite electrolytes utilizes the expansion stress induced by the electrolyte decomposition to in turn constrain the further decomposition of LGPS. Consequently, the S-MCI inherits the high dynamical stability of LPSCl-derived SEI and the lithiophilic affinity of Li-Ge alloy in LGPS-derived MCI. The Li||Li symmetric cells with the protection of S-MCI can operate stably for 1500 h at 0.5 mA cm and 0.5 mAh cm . The Li||NCM622 full cells present stable cycling for 100 cycles at 0.1 C with a high-capacity retention of 93.7%. This work sheds fresh insight into constructing electrochemically stable interphase for high-performance ASSLMBs.
采用硫化物固体电解质的全固态锂金属电池（ASSLMBs）因其卓越的安全性和高能量密度而受到越来越多的关注。然而，硫化物电解质对锂金属的不稳定性会导致形成两种无效的界面相，即固体电解质界面（SEI）和混合导电界面（MCI），这会显著阻碍锂离子的快速传输，并导致锂不均匀沉积和界面持续降解。在本研究中，通过原位应力自限反应提出了一种动态稳定的混合导电界面（S-MCI），以实现锂金属与复合硫化物电解质（Li PS Cl（LPSCl）和Li GeP S（LGPS））的兼容性。复合电解质的合理设计利用了电解质分解产生的膨胀应力来反过来抑制LGPS的进一步分解。因此，S-MCI继承了LPSCl衍生的SEI的高动态稳定性和LGPS衍生的MCI中锂锗合金的亲锂性。具有S-MCI保护的锂||锂对称电池在0.5 mA cm 和0.5 mAh cm 条件下可稳定运行1500小时。锂||NCM622全电池在0.1 C下可稳定循环100次，高容量保持率为93.7%。这项工作为构建高性能ASSLMBs的电化学稳定界面提供了新的见解。
