Enabling high-capacity Li metal battery with PVDF sandwiched type polymer electrolyte

Mingyang Xin; Xin Lian; Xuejie Gao; Pingbo Xu; Wenbo Li; Feilong Dong; Aotian Zhang; Haiming Xie; Yulong Liu

doi:10.1016/j.jcis.2022.09.127

Enabling high-capacity Li metal battery with PVDF sandwiched type polymer electrolyte

J Colloid Interface Sci. 2023 Jan;629(Pt B):980-988. doi: 10.1016/j.jcis.2022.09.127. Epub 2022 Sep 28.

Authors

Mingyang Xin¹, Xin Lian¹, Xuejie Gao², Pingbo Xu¹, Wenbo Li¹, Feilong Dong¹, Aotian Zhang¹, Haiming Xie³, Yulong Liu⁴

Affiliations

¹ National & Local United Engineering Laboratory for Power Battery, Department of Chemistry, Northeast Normal University, Changchun 130024, China.
² Liaoning Key Laboratory of Lignocellulosic Chemistry and Biomaterials, College of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian 116034, China.
³ National & Local United Engineering Laboratory for Power Battery, Department of Chemistry, Northeast Normal University, Changchun 130024, China. Electronic address: xiehm136@nenu.edu.cn.
⁴ National & Local United Engineering Laboratory for Power Battery, Department of Chemistry, Northeast Normal University, Changchun 130024, China. Electronic address: liuyl290@nenu.edu.cn.

PMID: 36208610
DOI: 10.1016/j.jcis.2022.09.127

Abstract

Polyvinylidene difluoride (PVDF) is one of the most attractive electrolyte materials for solid-state batteries due to its high ionic conductivity, however, the battery performance is limited by the high electrolyte-electrode interfacial resistance. Herein, PVDF polymer mixed with ceramic Li₇La₃Zr₂O₁₂ is coated on cellulose support membrane (PLCSM) through a simple slurry-casting method. The ionic transport of PLCSM is originated from dimethyl formamide (DMF)-Li⁺ solvation structure, which plays a critical role in conducting lithium ions. β-PVDF after dehydrofluorination offers a high dielectric constant and enhances the dissociation of lithium salt. As a result, PLCSM with a total thickness of 85 µm presents an oxidation voltage of 4.9 V. Li-Li symmetric cells by employing PLCSM reveal that the critical current density (CCD) is increased to 1 mA cm^-2. A full cell of LiFePO₄ |PLCSM |Li with high mass loading (1.2 mA h cm^-2) shows a first-cycle discharge capacity of 160 mA h g^-1. With LiNi_0.6Mn_0.2Co_0.2O₂ as the cathode, the initial discharge capacity is 153 mA h g^-1, and the capacity retention after 80 cycles is 80 %. The sandwiched PLCSM provides an effective strategy to achieve high-performance dendrite-free Li metal batteries.

Keywords: Cellulose membrane; Composite polymer electrolyte; Li metal; PVDF; Sandwich structure.