Cathode Evolution Track for Evaluating Commercial Lithium-Ion Battery Attenuation through Ar Ion Beam Cutting

作者：Liu, Jinchao^*; Wu, Yinlong; Yin, Shiheng; Yang, Xianfeng; Song, Shuqin

来源：Energy and Fuels, 2023, 37(13): 9662-9671.

DOI：10.1021/acs.energyfuels.3c01099

• MECHANISMS

The cathode is crucial for lithium-ion (Li-ion) batteries,andits corresponding investigation is also a hot issue in the scientificresearch and engineering field. The textile of the active particlesand interface of the cathode components determine the rate capabilityand lifetime of the Li-ion batteries. To study the interface, it isvital and necessary to obtain and track the real cross section ofthe cathode, which can reflect the real state of each part of thecathode and the combination between them. In this work, an optimizedAr ion beam cutting has been employed to prepare both contamination-freeand stress-free cross sections of the commercial Li-ion battery cathodefor the first time. As seen from the scanning electron microscopy(SEM) images, the as-prepared cross section of the above cathode isflat with full exposure of the inner textile of cathode active particles.It can be inferred that there exists a Co element accumulation regionin the original Li-ion battery cathode in the form of LiCoO2 (rhombohedral) according to the X-ray diffraction (XRD) and transmissionelectron microscopy (TEM) results. Moreover, along with Li-ion batteryaging, it can be found that cathode expansion and disappearance ofthe Co element accumulation region occur, indicating that the collapseof the LiCoO2 (rhombohedral) structure reduces the sitesof Li-ion storage and destroys the conductive network of the electrodes,thus resulting in the decrease of the voltage plateau and capacityattenuation of the Li-ion batteries. The present work could providea good avenue by tracking the cathode evolution to evaluate the Li-ionbattery attenuation during cycling performance.

• 单位
  中山大学