Microwave sintering and in-situ transmission electron microscopy heating study of Li 1.2(Mn 0.53Co 0.27) O2 with improved electrochemical performance

Jingjing Wu, Xialin Liu, Han Bi, Yuanzhe Song, Chao Wang, Qi Cao, Zhengwang Liu, Min Wang, Renchao Che, 2016

Image courtesy of J. Power Sources

Abstract

Li1·2(Mn0·53Co0.27)O2 cathode material was successfully synthesized using a microwave sintering method. The as-prepared material remained in an octahedral shape after sintering at 800 °C with a rapid heating rate of 35 °C min−1. The as-prepared sample was demonstrated to have better electrochemical performance than that synthesized using a conventional method. The enhanced electrochemical performance can be ascribed to the minor change in material morphology and less particle agglomeration in the macroscopic scale, which depends on the rapid-sintering mechanism provided by microwave sintering. The rapid-sintering mechanism was studied in an in-situ transmission electron microscopy (TEM) heating experiment, which directly presented the crystal growth process and the evidence for the morphological damage of Li1·2(Mn0·53Co0.27)O2 materials at approximately 830 °C.

Impact Statement

Microwaved sintered Li 1.2(Mn 0.53Co 0.27) O2 cathode materials were heated to 900C to investigate their structural degradation and agglomeration. Not only the samples showed better electrochemical performance compared to the conventionally sintered sample, in situ heating revealed that upon heating the sample transformed to a defect free and stable crystal morphology. Using the Aduro system in both SEM and TEM
enabled the researcher to study the heating characteristics of their sample in both micro and nanoscale.