In-plane grain boundary induced defect state in hierarchical NiCo-LDH and effect on battery-type charge storage  

作　　者：Jinjin Ban Xiaohan Wen Honghong Lei Guoqin Cao Xinhong Liu Chunyao Niu Guosheng Shao Junhua Hu 

机构地区：[1]School of Materials Science and Engineering,Industrial Technology Research Institute of Resource and Materials of Henan Province,Zhengzhou University,Zhengzhou 450001,China [2]State Center for International Cooperation on Designer Low-carbon&Environmental Materials(CDLCEM),Zhengzhou University,100 Kexue Avenue,Zhengzhou 450001,China [3]Henan Provincial Key Laboratory for Metal Fuel Battery,Foguang Power Generation Equipment Co.Ltd,50 Holly Street,Zhengzhou 450000,China [4]International Laboratory for Quantum Functional Materials of Henan,School of Physics and Microelectronics,Zhengzhou University,Zhengzhou 450001,China

出　　处：《Nano Research》2023年第4期4908-4916,共9页纳米研究（英文版）

基　　金：financial support from the National Natural Science Foundation of China(Nos.52171082 and 51001091);the Program for Innovative Research Team(in Science and Technology)in University of Henan Province(No.21IRTSTHN003);supported by the provincial scientific research program of Henan(No.182102310815);Nuclear Material Technology Innovation Fund for National Defense Technology Industry(No.ICNM-2021-YZ-02).

摘　　要：Domain boundaries are regarded as the effective active sites for electrochemical energy storage materials due to defects enrichment therein.However,layered double hydroxides(LDHs)tend to grow into single crystalline nano sheets due to their unique two-dimentional(2D)lattice structure.Previously,much efforts were made on the designing hierarchical structure to provide more exposed electroactive sites as well as accelerate the mass transfer.Herein,we demonstrate a strategy to introduce low angle grain boundary(LAGB)in the flakes of Ni/Co layered double hydroxides(NiCo-LDHs).These defect-rich nano flakes were self-assembled into hydrangea-like spheres that further constructed hollow cage structure.Both the formation of hierarchical structure and grain boundaries are interpreted with the synergistic effect of Ni2+/Co2+ratio in an“etching-growth”process.The domain boundary defect also results in the preferential formation of oxygen vacancy(Vo).Additionally,density functional theory(DFT)calculation reveals that Co substitution is a critical factor for the formation of adjacent lattice defects,which contributes to the formation of domains boundary.The fabricated battery-type Faradaic NiCo-LDH-2 electrode material exhibits significantly enhanced specific capacitance of 899 C·g^(−1)at a current density of 1 A·g^(−1).NiCo-LDH-2//AC asymmetric capacitor shows a maximum energy density of 101.1 Wh·kg^(−1)at the power density of 1.5 kW·kg^(−1).

关 键 词：sacrificial template grain boundary oxygen vacancy(Vo) hierarchical structure 

分 类 号：O64[理学—物理化学]