Enhanced Electrochemical Performance of LiNi0.6Co0.2Mn0.2O2 by Expanded Graphite. Issue 11 (22nd August 2019)

• Record Type: Journal Article
• Authors: Peng, Zhenfeng; Tang, Wenjie; Peng, Yujia; Qiu, Yang; Shuai, Hantao; Wang, Guixin
• Is Part Of: Energy technology. Volume 7:Issue 11(2019:Nov.)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-08-22
• Subjects: electrochemical performance -- expanded graphite -- high temperature -- hydrothermal treatment -- LiNi0.6Co0.2Mn0.2O2; Energy development -- Periodicals; Power resources -- Periodicals; 333.79
• DOI: 10.1002/ente.201900614
• Languages: English
• ISSNs: 2194-4288

Abstract

Abstract : High‐capacity ternary materials are attractive for the development of electric vehicles for long‐distance driving, but they still face some challenges. To improve the performance, expanded graphite (EG) with a unique loose‐layered structure is mixed with (Ni0.6 Co0.2 Mn0.2 )(OH)2 and LiOH·H2 O aqueous solution to supply microscale reaction space and limit grain growth via hydrothermal treatment as well as accommodate LiNi0.6 Co0.2 Mn0.2 O2 (NCM622) particles between the graphene layers. The key factors affecting electrochemical performance are investigated using various techniques. The NCM622 sample synthesized by adding 6.6 wt% of EG (PEG6.6%) exhibits the best performance. EG improves the discharge capacity of NCM622 from 156 to 175 mAh g −1 after 50 cycles at 1 C. As the surrounding temperature increases to 60 °C, the sample also shows good cyclability at 1 C, the 50th discharge specific capacity remains 153 mAh g −1 and the capacity retention rate is 82.3%, which is much higher than that of NCM622. Also, the columbic efficiency of NCM622 after 50 cycles improves from 69% to 99% with EG. The possible enhanced mechanism of NCM622 by EG is discussed. The effective way to enhance the performance using the layered structure of EG is promising for other energy materials. Abstract : The electrochemical performance of LiNi0.6 Co0.2 Mn0.2 O2 is greatly improved by expanded graphite (EG) via a facile hydrothermal treatment. The effects of EG on electrochemical performance and structure are investigated using different techniques. The possible EG‐enhancing mechanisms for LiNi0.6 Co0.2 Mn0.2 O2 are discussed.