Chinese Journal of Applied Chemistry ›› 2017, Vol. 34 ›› Issue (1): 71-75.DOI: 10.11944/j.issn.1000-0518.2017.01.160455

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La3+-doped NiCo Layered Double Hydroxide Nanosheets and Their Supercapacitive Performance

LI Gonga,CHEN Kunfengb,JIN Jingyia*(),XUE Dongfengb*()   

  1. aDepartment of Chemistry,Yanbian University,Yanji,Jilin 133002,China
    bState Key Laboratory of Rare Earth Resource Utilization,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022,China
  • Received:2016-11-10 Accepted:2016-11-17 Published:2017-01-03 Online:2017-01-03
  • Contact: JIN Jingyi,XUE Dongfeng
  • Supported by:
    Supported by the National Natural Science Foundation of China(No.91434118, No.21521092), External Cooperation Program of BIC, Chinese Academy of Sciences(No.121522KYS820150009), Jilin Provincial Science and Technology Development Program(No.20160520002JH)

Abstract:

NiCo layered double hydroxides(NiCo-LDHs) are important electrode materials in batteries and supercapacitors, due to its layered structure and controllable ratio and kind of metal ions. In this paper, we studied the effect of La3+ ions on the crystal structures and electrochemical performances of NiCo-LDHs. According to ionic electronegativity, the values of La3+(1.327) and Co2+(1.377) are similar, leading to the replace of Co2+ by La3+ in La3+-doped NiCo-LDHs. La3+-doped NiCo-LDHs show high specific capacitance and rate performance, 1115 F/g at 1 A/g and 517 F/g at 30 A/g, respectively. XRD, FTIR and SEM prove that La3+ doping does not change the structures of NiCo-LDHs. However, CV and electrochemical impendence spectrum confirms that the nature of electron or ion transfer is adjusted by La3+ doping. Owing to the size effect of La3+ ions, the optimized ratio of La doping is 0.26%. La3+ ions doping in electrode materials can be a promising method to change their nature of electron or ion transfer(electron or ion conductivity).

Key words: layered double hydroxide, rare earth ion, doping, supercapacitor