Structural evolution of plasma sprayed amorphous Li4Ti5O12 electrode and ceramic/polymer composite electrolyte during electrochemical cycle of quasi-solid-state lithium battery

Lingxiao Lan,Xinghua Liang,Xi Wu,Suo Li,Xiaofeng Zhang,Qixin Gai

doi:10.1007/s40145-020-0447-9

Abstract

A quasi-solid-state lithium battery is assembled by plasma sprayed amorphous Li4Ti5O12 (LTO) electrode and ceramic/polymer composite electrolyte with a little liquid electrolyte (10 µL/cm2) to provide the outstanding electrochemical stability and better normal interface contact. Scanning Electron Microscope (SEM), Scanning Transmission Electron Microscopy (STEM), Transmission Electron Microscopy (TEM), and Energy Dispersive Spectrometer (EDS) were used to analyze the structural evolution and performance of plasma sprayed amorphous LTO electrode and ceramic/polymer composite electrolyte before and after electrochemical experiments. By comparing the electrochemical performance of the amorphous LTO electrode and the traditional LTO electrode, the electrochemical behavior of different electrodes is studied. The results show that plasma spraying can prepare an amorphous LTO electrode coating of about 8 µm. After 200 electrochemical cycles, the structure of the electrode evolved, and the inside of the electrode fractured and cracks expanded, because of recrystallization at the interface between the rich fluorine compounds and the amorphous LTO electrode. Similarly, the ceramic/polymer composite electrolyte has undergone structural evolution after 200 test cycles. The electrochemical cycle results show that the cycle stability, capacity retention rate, coulomb efficiency, and internal impedance of amorphous LTO electrode are better than traditional LTO electrode. This innovative and facile quasi-solid-state strategy is aimed to promote the intrinsic safety and stability of working lithium battery, shedding light on the development of next-generation high-performance solid-state lithium batteries.

Highlights

Compared with traditional rechargeable lithium batteriesJ Adv Ceram 2021, 10(2): 347–354Frequency Magnetron Sputtering Deposition (RFMSD) [2], Pulsed Laser Deposition (PLD) [3], Electron Beam Evaporation (EBE) [4], Chemical Vapor Deposition (CVD) [5], Molecular Beam Epitaxy (MBE) [6], and other methods [7]
The flexible electrolyte film with ceramic/polymer based composite was prepared by mechanical mixing and mold casting
The capacity retention rate of the traditional LTO electrode dropped to 9% at a rate of 0.2 C, dropped to 0% when the rate exceeded 0.3 C, and returned to 13% at a rate of 0.1 C

Summary

Introduction

Frequency Magnetron Sputtering Deposition (RFMSD) [2], Pulsed Laser Deposition (PLD) [3], Electron Beam Evaporation (EBE) [4], Chemical Vapor Deposition (CVD) [5], Molecular Beam Epitaxy (MBE) [6], and other methods [7]. The ceramic electrolyte channels provide continuous pathways, which help in maintaining a high ionic conductivity between the electrodes, while the polymer channels permit improvement of the mechanical properties compared to those of the ceramic alone, in particular, mitigation of the brittleness of ceramics In this contribution, the plasma spraying and fast cooling methods were used to prepare the amorphous thin LTO electrode on the perforated copper foil. The plasma sprayed method of preparing amorphous electrodes and applying them to quasi-solid batteries was adopted in this work to improve electrochemical stability. This innovative and quasi-solid-state lithium battery strategy aims to provide a new way to enhance electrochemical cycle performance of quasi-solid-state lithium battery

Experimental

Results and discussion

Conclusions