Cation-vacancy induced Li+ intercalation pseudocapacitance at atomically thin heterointerface for high capacity and high power lithium-ion batteries  

作　　者：Ding Yuan David Adekoya Yuhai Dou Yuhui Tian Hao Chen Zhenzhen Wu Jiadong Qin Linping Yu Jian Zhang Xianhu Liu Shi Xue Dou Shanqing Zhang 

机构地区：[1]Centre for Clean Environment and Energy,School of Environment and Science,Gold Coast Campus,Griffith University,Gold Coast 4222,Australia [2]Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation,Changsha University of Science and Technology,Changsha 410114,Hunan,China [3]National Engineering Research Centre for Advanced Polymer Processing Technology,Zhengzhou University,Zhengzhou 450002,Henan,China [4]Institute for Superconducting and Electronic Materials,University of Wollongong Australia,Wollongong 2500,Australia

出　　处：《Journal of Energy Chemistry》2021年第11期281-288,I0006,共9页能源化学（英文版）

基　　金：This work was financially supported by the Australian Research Council(ARC)Discovery Projects(DP210103266,DP200100965 and DP200100365);the ARC Discovery Early Career Researcher Award(DE210101102);the Griffith University Postdoctoral Fellowship Scheme(YUDOU 036 Research Internal).

摘　　要：It is challenging to create cation vacancies in electrode materials for enhancing the performance of rechargeable lithium ion batteries (LIBs). Herein, we utilized a strong alkaline etching method to successfully create Co vacancies at the interface of atomically thin Co_(3−x)O_(4)/graphene@CNT heterostructure for high-energy/power lithium storage. The creation of Co-vacancies in the sample was confirmed by high-resolution scanning transmission electron microscope (HRSTEM), X-ray photoelectron spectroscopy (XPS) and electron energy loss near-edge structures (ELNES). The obtained Co_(3−x)O_(4)/graphene@CNT delivers an ultra-high capacity of 1688.2 mAh g^(−1) at 0.2 C, excellent rate capability of 83.7% capacity retention at 1 C, and an ultralong life up to 1500 cycles with a reversible capacity of 1066.3 mAh g^(−1). Reaction kinetic study suggests a significant contribution from pseudocapacitive storage induced by the Co-vacancies at the Co_(3−x)O_(4)/graphene@CNT interface. Density functional theory confirms that the Co-vacancies could dramatically enhance the Li adsorption and provide an additional pathway with a lower energy barrier for Li diffusion, which results in an intercalation pseudocapacitive behavior and high-capacity/rate energy storage.

关 键 词：Cation vacancy Atomically thin Interface PSEUDOCAPACITANCE Lithium-ion batteries 

分 类 号：TM912[电气工程—电力电子与电力传动] TB34[一般工业技术—材料科学与工程]