Hybrid Crosslinked Solid Polymer Electrolyte via In‐Situ Solidification Enables High‐Performance Solid‐State Lithium Metal Batteries

• Published in: Advanced materials (Weinheim) 2023-11, Vol.35 (47), p.e2304686-n/a
• Main Authors: Mu, Kexin, Wang, Dai, Dong, Weiliang, Liu, Qiang, Song, Zhennuo, Xu, Weijian, Yao, Pingping, Chen, Yin'an, Yang, Bo, Li, Cuihua, Tian, Lei, Zhu, Caizhen, Xu, Jian
• Format: Article
• Language: English
• Subjects: Crosslinking; Electrolytes; high‐performance; hybrid crosslinked polymer electrolyte; Interface reactions; Interface stability; in‐situ solidification; Ion currents; ionic conductivity; Lithium; Lithium batteries; Materials science; Organic/inorganic hybrid polymers; Polyethers; Safety; Solidification; Solids; solid‐state lithium metal batteries
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202304686

Solid‐state lithium‐metal batteries constructed by in‐situ solidification of cyclic ether are considered to be a critical strategy for the next generation of solid‐state batteries with high energy density and safety. However, the poor thermal/electrochemical stability of linear polyethers and severe interfacial reactions limit its further development. Herein, in‐situ ring‐opening hybrid crosslinked polymerization is proposed for organic/inorganic hybrid polymer electrolyte (HCPE) with superior ionic conductivity of 2.22 × 10−3 S cm−1 at 30 °C, ultrahigh Li+ transference number of 0.88, and wide electrochemical stability window of 5.2 V. These allow highly stable lithium stripping/plating cycling for over 1000 h at 1 mA cm−2, which also reveal a well‐defined interfacial stabilization mechanism. Thus, HCPE endows assembled solid‐state lithium‐metal batteries with excellent long‐cycle performance over 600 cycles at 2 C (25 °C) and superior capacity retention of 92.1%. More importantly, the proposed noncombustible HCPE opens up a new frontier to promote the practical application of high safety and high energy density solid‐state batteries via in‐situ solidification. A novel design of a hybrid crosslinked solid polymer electrolyte (HCPE), which is prepared by in situ solidification at room temperature, is reported. Lithium metal cells with this HCPE have the advantages of high ionic conductivity (2.22 × 10−3 S cm−1 at 30 °C), high electrochemical window (5.2 V), high lithium‐ion transference number (0.88), and long lifetime (>600 cycles) at room temperature (25 °C).