Xu Jieru, Li Jiuming, Li Yongxing, Yang Ming, Chen Liquan, Li Hong, Wu Fan
Key Laboratory for Renewable Energy, Beijing Key Laboratory for New Energy Materials and Devices, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
College of Materials Science and Opto-Electronic Technology, School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
Adv Mater. 2022 Aug;34(34):e2203281. doi: 10.1002/adma.202203281. Epub 2022 Jul 21.
An ultrastable and kinetically favorable interface is constructed between sulfide-poly(ethylene oxide) (PEO) composite solid electrolytes (CSEs) and lithium metal, via in situ formation of a solid electrolyte interphase (SEI) layer containing Li PS . A specially designed sulfide, lithium polysulfidophosphate (LPS), can distribute uniformly in the PEO matrix via a simple stirring process because of its complete solubility in acetonitrile solvent, which is advantageous for creating a homogeneous SEI layer. The CSE/Li interface with high Li transportation capability is stabilized quickly through in situ formation of a Li PS /Li S/LiF layer via the reaction between LPS and lithium metal to inhibit lithium dendrite growth. A Li/Li symmetric cell with the LPS-integrated CSE exhibits constant and small CSE/Li resistance of 10 Ω cm during cycling, delivering stable cycling for 3475 h at a current density of 0.2 mA cm and a high critical current density of 0.9 mA cm at 60 °C. Impressive electrochemical performance is also demonstrated for LiFePO /CSE/Li all-solid-state batteries with capacity of 127.6 mAh g after 1000 cycles at 1 C.
通过原位形成含Li₂PS₃的固体电解质界面（SEI）层，在硫化物-聚环氧乙烷（PEO）复合固体电解质（CSE）与锂金属之间构建了一个超稳定且动力学有利的界面。一种经过特殊设计的硫化物，聚硫代磷酸锂（LPS），由于其在乙腈溶剂中完全可溶，能够通过简单搅拌过程均匀分布在PEO基体中，这有利于形成均匀的SEI层。通过LPS与锂金属之间的反应原位形成Li₂PS₃/Li₂S/LiF层，抑制锂枝晶生长，快速稳定了具有高锂传输能力的CSE/Li界面。具有集成LPS的CSE的Li/Li对称电池在循环过程中表现出恒定且较小的CSE/Li电阻，为10 Ω·cm²，在60℃下，在0.2 mA·cm²的电流密度下可稳定循环3475 h，临界电流密度高达0.9 mA·cm²。对于LiFePO₄/CSE/Li全固态电池，在1 C下循环1000次后容量为127.6 mAh·g⁻¹，也展示出令人印象深刻的电化学性能。
