Understanding the origin of the improved sodium ion storage performance of the transition metal oxide@carbon nanocomposite anodes

Xin-Tao Yang; Ting-Yi Huang; Yao-Hui Wang; Jin-Chao Dong; Qiu-Long Wei; Hua Zhang; Xiu-Mei Lin; Jian-Feng Li

doi:10.1063/5.0149871

Understanding the origin of the improved sodium ion storage performance of the transition metal oxide@carbon nanocomposite anodes

J Chem Phys. 2023 May 7;158(17):174708. doi: 10.1063/5.0149871.

Authors

Xin-Tao Yang¹, Ting-Yi Huang¹, Yao-Hui Wang¹, Jin-Chao Dong¹, Qiu-Long Wei¹, Hua Zhang¹, Xiu-Mei Lin^{1

2}, Jian-Feng Li^{1

3}

Affiliations

¹ College of Materials, College of Energy, College of Chemistry and Chemical Engineering, State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, Xiamen University, Xiamen 361005, China.
² Department of Chemistry and Environment Science, Fujian Province University Key Laboratory of Analytical Science, Minnan Normal University, Zhangzhou 363000, China.
³ Shenzhen Research Institute of Xiamen University, Shenzhen 518000, China.

PMID: 37144711
DOI: 10.1063/5.0149871

Abstract

Transition metal oxide (TMO) anodes show inferior sodium ion storage performance compared with that of lithium ion storage owing to the larger radium size and heavier elemental mass of Na+ than Li+. Effective strategies are highly desired to improve the Na+ storage performance of TMOs for applications. In this work, using ZnFe2O4@xC nanocomposites as model materials for investigation, we found that by manipulating the particle sizes of the inner TMOs core and the features of outer carbon coating, the Na+ storage performance can be significantly improved. The ZnFe2O4@1C with a diameter of the inner ZnFe2O4 core of around 200 nm coated by a thin carbon layer of around 3 nm shows a specific capacity of only 120 mA h g-1. The ZnFe2O4@6.5C with a diameter of the inner ZnFe2O4 core of around 110 nm embedding in a porous interconnected carbon matrix displays a significantly improved specific capacity of 420 mA h g-1 at the same specific current. Furthermore, the latter shows an excellent cycling stability of 1000 cycles with a capacity retention of 90% of the initial 220 mA h g-1 specific capacity at 1.0 A g-1. TEM, electrochemical impedance spectroscopy, and kinetic analysis show that the inner ZnFe2O4 core with reduced particle size and the outer thicker and interconnected carbon matrix synergistically improve the active reaction sites, integrity, electric conductivity, and pseudocapacitive-controlled contribution of ZnFe2O4@xC nanocomposites, thus leading to an overall enhanced Na+ storage performance. Our findings create a universal, facile, and effective method to enhance the Na+ storage performance of the TMO@C nanomaterials.