Effect of Particle Size on the Sodium Ions Utilization Efficiency of Zeolite-Templated Carbon as the Anode in a Sodium Ion Battery

Abstract

A series of zeolite-templated carbon (ZTC) with particle sizes of 1 μm, 70 nm, and 10 nm have been prepared. The external surface area and diffusion path of Na+ inside the ZTC was varied by controlling the size of the zeolite crystals used as templates. The three ZTC samples have been used to store sodium cations (Na+) for the purpose of sodium-ion batteries (SIB). It was found that the ZTC with a particle size of 10 nm exhibited the highest first discharge capacity of 2116 mAh·g–1 at a current density of 0.1 mA·g–1 due to the highest external surface area and more complete filling of the internal pore volume of the ZTC. While the ZTC with 70 nm particle size showed better reversible capacity of 180 mAh·g–1 at a current density of 0.1 mA·g–1, and the 10 nm size ZTC caused more electrolyte decomposition reaction and more solid electrolyte interphase (SEI) layer on the external surface of the crystals, resulting in a low first Coulombic efficiency and poor Na+ extraction.