Regulation of morphology and electronic configuration of NiCo2O4 by aluminum doping for high performance supercapacitors

Xing Chen; Lili Song; Mengyuan Zeng; Le Tong; Chuanxiang Zhang; Kun Xie; Yuqiao Wang

doi:10.1016/j.jcis.2021.12.049

Regulation of morphology and electronic configuration of NiCo₂O₄ by aluminum doping for high performance supercapacitors

J Colloid Interface Sci. 2022 Mar 15:610:70-79. doi: 10.1016/j.jcis.2021.12.049. Epub 2021 Dec 9.

Authors

Xing Chen¹, Lili Song², Mengyuan Zeng², Le Tong², Chuanxiang Zhang³, Kun Xie⁴, Yuqiao Wang⁵

Affiliations

¹ Center for Nano Photoelectrochemistry and Devices, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China; School of Environmental and Chemical Engineering, Chongqing Three Gorges University, Chongqing 404100, China.
² Center for Nano Photoelectrochemistry and Devices, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China.
³ School of Materials Science and Engineering, Nanjing Institute of Technology, Nanjing 211167, China.
⁴ School of Environmental and Chemical Engineering, Chongqing Three Gorges University, Chongqing 404100, China. Electronic address: xiekun_79@163.com.
⁵ Center for Nano Photoelectrochemistry and Devices, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China. Electronic address: yqwang@seu.edu.cn.

PMID: 34922083
DOI: 10.1016/j.jcis.2021.12.049

Abstract

Morphology engineering and element doping are two effective strategies to boost the capacitive performance of electroactive materials. The morphology control through doping process is conducive to simplifying the preparation process. Herein, an aluminum-doped (Al-doped) strategy was used to prepare Al-doped NiCo₂O₄ nanosheet-wire structure (Al-NiCo₂O₄ NSW) by hydrothermal method and subsequent calcination. The nanosheet-wire structure was composed of one-dimensional (1D) nanowires and two-dimensional (2D) ultrathin nanosheets. 1D nanowires can provide efficient pathways for the electrons/ions transport. 2D nanosheets can enlarge the specific surface area and expose more active sites. The Al doping can change the electronic structure of NiCo₂O₄ with enhanced electrical conductivity as revealed by density functional theory (DFT) calculations. Meanwhile, a strong adsorption capacity of OH^- was obtained on Al-NiCo₂O₄ NSW for redox reactions. The Al-NiCo₂O₄ NSW electrode demonstrated a high specific capacity of 1441C g^-1 (2446F g^-1) at 1 A g^-1 and excellent cycling stability (87.6% capacity retention at 10 A g^-1 for 5000 charge-discharge cycles). The assembled asymmetric supercapacitor manifested a superior energy density of 46.2 Wh Kg^-1 at a power density of 800 W kg^-1.

Keywords: Absorption energy; Al doping; Density functional theory; NiCo(2)O(4); Supercapacitor.