Mn and Co co-doped perovskite fluorides KNiF3 with enhanced capacitive performance

Hongguang Fan; Xu Zhang; Youcheng Wang; Rongjie Gao; Junwei Lang

doi:10.1016/j.jcis.2019.09.051

Mn and Co co-doped perovskite fluorides KNiF₃ with enhanced capacitive performance

J Colloid Interface Sci. 2019 Dec 1:557:546-555. doi: 10.1016/j.jcis.2019.09.051. Epub 2019 Sep 16.

Authors

Hongguang Fan¹, Xu Zhang², Youcheng Wang¹, Rongjie Gao³, Junwei Lang⁴

Affiliations

¹ Laboratory of Clean Energy Chemistry and Materials, Lanzhou Institute of Chemical Physics, Lanzhou 730000, PR China; Qingdao Center of Resource Chemistry & New Materials, Qingdao 266000, PR China; Department of Material Science and Engineering, Ocean University of China, Qingdao 266100, PR China.
² Laboratory of Clean Energy Chemistry and Materials, Lanzhou Institute of Chemical Physics, Lanzhou 730000, PR China.
³ Department of Material Science and Engineering, Ocean University of China, Qingdao 266100, PR China. Electronic address: dmh206@ouc.edu.cn.
⁴ Laboratory of Clean Energy Chemistry and Materials, Lanzhou Institute of Chemical Physics, Lanzhou 730000, PR China; Qingdao Center of Resource Chemistry & New Materials, Qingdao 266000, PR China. Electronic address: jwlang@licp.cas.cn.

PMID: 31550647
DOI: 10.1016/j.jcis.2019.09.051

Abstract

Perovskite-based aqueous supercapacitors have important development prospects due to their advantages of high energy density, low cost, environmental benignity. Here, bimetallic Ni-Mn and trimetallic Ni-Co-Mn perovskite fluorides are prepared via facile solvothermal method and characterized as positive electrode materials for supercapacitors. The structure, composition, chemical states and the electrochemical properties of these samples are investigated in detail. Three electrode measurements indicate that the electrochemical properties of the perovskite fluorides KNiF₃ depend on the nature and amount of dopants. Partial doping of Ni by Mn increases the rate capability but decreases the specific capacity, while Co and Mn co-doping improve both the rate capability and specific capacity of perovskite fluoride KNiF₃. The K-Ni-Co-Mn-F (Ni/Co/Mn = 12:2:1) sample exhibits the maximum specific capacity of 211 mAh g^-1, low internal resistance and a high rate capability (82% capacity retention from 1 to 16 A g^-1). Furthermore, the AC//K-Ni-Co-Mn-F (Ni/Co/Mn = 12:2:1) asymmetric supercapacitor delivers a maximum energy density of 50.2 Wh kg^-1. These results prove that Co and Mn co-doped KNiF₃ can be a promising material for supercapacitor.

Keywords: Doping; Perovskite fluoride; Pseudocapacitive behavior; Rate capability; Supercapacitor.