Phase regulation enabling dense polymer-based composite electrolytes for solid-state lithium metal batteries

• Published in: Nature communications 2023-10, Vol.14 (1), p.6296-6296, Article 6296
• Main Authors: Wu, Qian, Fang, Mandi, Jiao, Shizhe, Li, Siyuan, Zhang, Shichao, Shen, Zeyu, Mao, Shulan, Mao, Jiale, Zhang, Jiahui, Tan, Yuanzhong, Shen, Kang, Lv, Jiaxing, Hu, Wei, He, Yi, Lu, Yingying
• Format: Article
• Language: English
• Subjects: 140/146; 147/135; 147/143; 639/301/299/891; 639/4077/4079/891; 639/638/675; Batteries; Composite materials; Conductivity; Dielectric constant; Electrolytes; Electrolytic cells; Fluorides; Humanities and Social Sciences; Ion currents; Ions; Lithium; Lithium batteries; Molten salt electrolytes; Molybdenum compounds; multidisciplinary; Polymers; Polyvinylidene fluorides; Room temperature; Science; Science (multidisciplinary); Solid electrolytes; Solid state; Solvation; Solvents; Vinylidene fluoride
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-41808-3

Solid polymer electrolytes with large-scale processability and interfacial compatibility are promising candidates for solid-state lithium metal batteries. Among various systems, poly(vinylidene fluoride)-based polymer electrolytes with residual solvent are appealing for room-temperature battery operations. However, their porous structure and limited ionic conductivity hinder practical application. Herein, we propose a phase regulation strategy to disrupt the symmetry of poly(vinylidene fluoride) chains and obtain the dense composite electrolyte through the incorporation of MoSe 2 sheets. The electrolyte with high dielectric constant can optimize the solvation structures to achieve high ionic conductivity and low activation energy. The in-situ reactions between MoSe 2 and Li metal generate Li 2 Se fast conductor in solid electrolyte interphase, which improves the Coulombic efficiency and interfacial kinetics. The solid-state Li||Li cells achieve robust cycling at 1 mA cm −2 , and the Li||LiNi 0.8 Co 0.1 Mn 0.1 O 2 full cells show practical performance at high rate (3C), high loading (2.6 mAh cm −2 ) and in pouch cell. Polymer electrolytes based on poly(vinylidene fluoride) with residual solvents are appealing for room-temperature battery operations. Here, the authors present a phase regulation approach to achieve a dense electrolyte and enhance ionic conductivity through the incorporation of MoSe 2 sheets.