Polydopamine-Coated Garnet Particles Homogeneously Distributed in Poly(propylene carbonate) for the Conductive and Stable Membrane Electrolytes of Solid Lithium Batteries

Mengyang Jia; Ning Zhao; Zhijie Bi; Zhengqian Fu; Fangfang Xu; Chuan Shi; Xiangxin Guo

doi:10.1021/acsami.0c13434

Polydopamine-Coated Garnet Particles Homogeneously Distributed in Poly(propylene carbonate) for the Conductive and Stable Membrane Electrolytes of Solid Lithium Batteries

ACS Appl Mater Interfaces. 2020 Oct 14;12(41):46162-46169. doi: 10.1021/acsami.0c13434. Epub 2020 Sep 30.

Authors

Mengyang Jia¹, Ning Zhao¹, Zhijie Bi¹, Zhengqian Fu², Fangfang Xu², Chuan Shi¹, Xiangxin Guo¹

Affiliations

¹ College of Physics, Qingdao University, Qingdao 266071, China.
² Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China.

PMID: 32935964
DOI: 10.1021/acsami.0c13434

Abstract

Flexible membrane electrolytes consisting of Li_6.4La₃Zr_1.4Ta_0.6O₁₂ (LLZTO) fillers in poly(propylene carbonate) (PPC) are considered promising for developing solid lithium batteries with high energy density and safety. However, LLZTO particles tend to agglomerate owing to their high surface energy, especially concerning their distribution in PPC that has low surface energy. Moreover, basic LLZTO particles attack PPC, resulting in its decomposition. Such problems make it difficult to achieve membrane electrolytes of PPC/LLZTO with high conduction and stability. In this work, continuous polydopamine (PDA) layers with a thickness of 4 nm are coated on LLZTO particles. Characterized by synchrotron X-ray microtomography and scanning electron microscopy, the PDA-coated LLZTO particles show homogeneous dispersion in PPC, which is attributed to the reduced surface energy of the LLZTO particles. Besides, this coating hinders the reaction between LLZTO and PPC, which improves the chemical stability of the membrane electrolytes. Consequently, the cells based on membrane electrolytes with PDA-coated LLZTO particles in PPC show improved electrochemical performance and cycling stability. These results demonstrate that the strategy of coating basic LLZTO particles is powerful for enhancing their usability in the high-performance membrane electrolytes for solid lithium batteries.

Keywords: LLZTO particles; PDA coating; PPC polymers; cycle stability; high conduction; interfacial stability.