Mingwei Zan, Hongsheng Xie, Sichen Jiao, Kai Jiang, Xuelong Wang, Ruijuan Xiao, Xiqian Yu, Hong Li, Xuejie Huang
{"title":"On the Much-Improved High-Voltage Cycling Performance of LiCoO2 by Phase Alteration from O3 to O2 Structure","authors":"Mingwei Zan, Hongsheng Xie, Sichen Jiao, Kai Jiang, Xuelong Wang, Ruijuan Xiao, Xiqian Yu, Hong Li, Xuejie Huang","doi":"10.1002/smsc.202400162","DOIUrl":null,"url":null,"abstract":"Lithium cobalt oxide (LiCoO<sub>2</sub>) is an irreplaceable cathode material for lithium-ion batteries with high volumetric energy density. The prevailing O<sub>3</sub> phase LiCoO<sub>2</sub> adopts the ABCABC (A, B, and C stand for lattice sites in the close-packed plane) stacking modes of close-packed oxygen atoms. Currently, the focus of LiCoO<sub>2</sub> development is application at high voltage (>4.55 V versus Li<sup>+</sup>/Li) to achieve a high specific capacity (>190 mAh g<sup>−1</sup>). However, cycled with a high cutoff voltage, O<sub>3</sub>–LiCoO<sub>2</sub> suffers from rapid capacity decay. The causes of failure are mostly attributed to the irreversible transitions to H1-3/O<sub>1</sub> phase after deep delithiation and severe interfacial reactions with electrolytes. In addition to O<sub>3</sub>, LiCoO<sub>2</sub> is also known to crystalize in an O<sub>2</sub> phase with ABAC stacking. Since its discovery, little is known about the high-voltage behavior of O<sub>2</sub>–LiCoO<sub>2</sub>. Herein, through systematic comparison between electrochemical performances of O<sub>3</sub> and O<sub>2</sub> LiCoO<sub>2</sub> at high voltage, the significantly better stability of O<sub>2</sub>–LiCoO<sub>2</sub> (>4.5 V) than that of O<sub>3</sub>–LiCoO<sub>2</sub> in the same micro-sized particle morphology is revealed. Combining various characterization techniques and multiscale simulation, the outstanding high-voltage stability of O<sub>2</sub>–LiCoO<sub>2</sub> is attributed to the high Li diffusivity and ideal mechanical properties. Uniform Li<sup>+</sup> distribution and balanced internal stress loading may hold the key to improving the high-voltage performance of LiCoO<sub>2</sub>.","PeriodicalId":29791,"journal":{"name":"Small Science","volume":null,"pages":null},"PeriodicalIF":11.1000,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Small Science","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1002/smsc.202400162","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Lithium cobalt oxide (LiCoO2) is an irreplaceable cathode material for lithium-ion batteries with high volumetric energy density. The prevailing O3 phase LiCoO2 adopts the ABCABC (A, B, and C stand for lattice sites in the close-packed plane) stacking modes of close-packed oxygen atoms. Currently, the focus of LiCoO2 development is application at high voltage (>4.55 V versus Li+/Li) to achieve a high specific capacity (>190 mAh g−1). However, cycled with a high cutoff voltage, O3–LiCoO2 suffers from rapid capacity decay. The causes of failure are mostly attributed to the irreversible transitions to H1-3/O1 phase after deep delithiation and severe interfacial reactions with electrolytes. In addition to O3, LiCoO2 is also known to crystalize in an O2 phase with ABAC stacking. Since its discovery, little is known about the high-voltage behavior of O2–LiCoO2. Herein, through systematic comparison between electrochemical performances of O3 and O2 LiCoO2 at high voltage, the significantly better stability of O2–LiCoO2 (>4.5 V) than that of O3–LiCoO2 in the same micro-sized particle morphology is revealed. Combining various characterization techniques and multiscale simulation, the outstanding high-voltage stability of O2–LiCoO2 is attributed to the high Li diffusivity and ideal mechanical properties. Uniform Li+ distribution and balanced internal stress loading may hold the key to improving the high-voltage performance of LiCoO2.
期刊介绍:
Small Science is a premium multidisciplinary open access journal dedicated to publishing impactful research from all areas of nanoscience and nanotechnology. It features interdisciplinary original research and focused review articles on relevant topics. The journal covers design, characterization, mechanism, technology, and application of micro-/nanoscale structures and systems in various fields including physics, chemistry, materials science, engineering, environmental science, life science, biology, and medicine. It welcomes innovative interdisciplinary research and its readership includes professionals from academia and industry in fields such as chemistry, physics, materials science, biology, engineering, and environmental and analytical science. Small Science is indexed and abstracted in CAS, DOAJ, Clarivate Analytics, ProQuest Central, Publicly Available Content Database, Science Database, SCOPUS, and Web of Science.