High-Entropy Polymer Electrolytes Derived from Multivalent Polymeric Ligands for Solid-State Lithium Metal Batteries with Accelerated Li+ Transport

Fangmin Ye; Zhixin Wang; Mengcheng Li; Jing Zhang; Dong Wang; Meinan Liu; Aiping Liu; Hongzhen Lin; Hee-Tak Kim; Jian Wang

doi:10.1021/acs.nanolett.4c00154

High-Entropy Polymer Electrolytes Derived from Multivalent Polymeric Ligands for Solid-State Lithium Metal Batteries with Accelerated Li⁺ Transport

Nano Lett. 2024 May 9. doi: 10.1021/acs.nanolett.4c00154. Online ahead of print.

Authors

Fangmin Ye¹, Zhixin Wang¹, Mengcheng Li¹, Jing Zhang², Dong Wang³, Meinan Liu⁴, Aiping Liu¹, Hongzhen Lin⁴, Hee-Tak Kim⁵, Jian Wang^{4

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Affiliations

¹ Key Laboratory of Optical Field Manipulation of Zhejiang Province, Department of Physics, Zhejiang Sci-Tech University, Hangzhou 310018, People's Republic of China.
² School of Materials Science and Engineering, Xi'an University of Technology, Xi'an 710048, People's Republic of China.
³ Key Laboratory of Automobile Materials of MOE, School of Materials Science and Engineering, Jilin University, Changchun 130012, People's Republic of China.
⁴ i-Lab & CAS Key Laboratory of Nanophotonic Materials and Devices, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, People's Republic of China.
⁵ Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Republic of Korea.
⁶ Helmholtz Institute Ulm (HIU), Ulm D89081, Germany.
⁷ Karlsruhe Institute of Technology (KIT) D76021 Karlsruhe, Germany.

PMID: 38721815
DOI: 10.1021/acs.nanolett.4c00154

Abstract

Solid-state polymer-based electrolytes (SSPEs) exhibit great possibilities in realizing high-energy-density solid-state lithium metal batteries (SSLMBs). However, current SSPEs suffer from low ionic conductivity and unsatisfactory interfacial compatibility with metallic Li because of the high crystallinity of polymers and sluggish Li⁺ movement in SSPEs. Herein, differing from common strategies of copolymerization, a new strategy of constructing a high-entropy SSPE from multivariant polymeric ligands is proposed. As a protocol, poly(vinylidene fluoride-co-hexafluoropropylene) (PH) chains are grafted to the demoed polyethylene imine (PEI) with abundant -NH₂ groups via a click-like reaction (HE-PEIgPHE). Compared to a PH-based SSPE, our HE-PEIgPHE shows a higher modulus (6.75 vs 5.18 MPa), a higher ionic conductivity (2.14 × 10^-4 vs 1.03 × 10^-4 S cm^-1), and a higher Li⁺ transference number (0.55 vs 0.42). A Li|HE-PEIgPHE|Li cell exhibits a long lifetime (1500 h), and a Li|HE-PEIgPHE|LiFePO₄ cell delivers an initial capacity of 160 mAh g^-1 and a capacity retention of 98.7%, demonstrating the potential of our HE-PEIgPHE for the SSLMBs.

Keywords: Li metal batteries; Li+ transport; Solid polymer electrolyte; high-entropy polymer; polymeric ligand.