In situ magnetometry study on the origin of anomalously capacity in transition metal sulfides
Yan Liu,
Yuanyuan Han,
Shuxuan Liao,
Fangchao Gu,
Hengjun Liu,
Xixiang Xu,
Zhiqiang Zhao,
Xiancheng Sang,
Qinghao Li,
Weijin Kong,
Qiang Li
Affiliations
Yan Liu
College of Physics, University-Industry Joint Center for Ocean Observation and Broadband Communication, Weihai Innovation Research Institute, Qingdao University, Qingdao 266071, China
Yuanyuan Han
College of Physics, University-Industry Joint Center for Ocean Observation and Broadband Communication, Weihai Innovation Research Institute, Qingdao University, Qingdao 266071, China
Shuxuan Liao
College of Physics, University-Industry Joint Center for Ocean Observation and Broadband Communication, Weihai Innovation Research Institute, Qingdao University, Qingdao 266071, China
Fangchao Gu
College of Physics, University-Industry Joint Center for Ocean Observation and Broadband Communication, Weihai Innovation Research Institute, Qingdao University, Qingdao 266071, China
Hengjun Liu
College of Physics, University-Industry Joint Center for Ocean Observation and Broadband Communication, Weihai Innovation Research Institute, Qingdao University, Qingdao 266071, China
Xixiang Xu
College of Physics, University-Industry Joint Center for Ocean Observation and Broadband Communication, Weihai Innovation Research Institute, Qingdao University, Qingdao 266071, China
Zhiqiang Zhao
College of Physics, University-Industry Joint Center for Ocean Observation and Broadband Communication, Weihai Innovation Research Institute, Qingdao University, Qingdao 266071, China
Xiancheng Sang
College of Physics, University-Industry Joint Center for Ocean Observation and Broadband Communication, Weihai Innovation Research Institute, Qingdao University, Qingdao 266071, China
Qinghao Li
College of Physics, University-Industry Joint Center for Ocean Observation and Broadband Communication, Weihai Innovation Research Institute, Qingdao University, Qingdao 266071, China
Weijin Kong
College of Physics, University-Industry Joint Center for Ocean Observation and Broadband Communication, Weihai Innovation Research Institute, Qingdao University, Qingdao 266071, China
Qiang Li
Corresponding author.; College of Physics, University-Industry Joint Center for Ocean Observation and Broadband Communication, Weihai Innovation Research Institute, Qingdao University, Qingdao 266071, China
Cobalt sulfides are considered as promising candidates for lithium-ion battery (LIB) anode materials with high energy densities. Their energy storage mechanism is widely understood to involve the traditional intercalation and conversion reaction. However, these conventional mechanisms are unable to explain the storage capacities of certain materials which exceed the theoretical limit. Here, utilizing advanced in situ magnetometry to detect the magnetization evolution of Co1-xS LIBs in real time, it is demonstrated that the Co-catalytic lithium storage process and interfacial space charge storage mechanism are strongly related to the additional capacity of cobalt sulfides. During discharge, a Co/Li2S interface is formed, wherein the Co nanoparticles and Li2S could store a large amount of polarized electrons Li+, respectively. Subsequently, the electrons stored in Co are transferred to the polymeric film, forming radical anions and contributing extra capacity. These findings reveal the charge storage mechanisms of transition metal sulfides and highlight the critical role of magnetic testing in the investigation of energy storage mechanisms.
