A Li3PO4 coating strategy to enhance the Li-ion transport properties of Li2ZnTi3O8 anode material for Lithium-ion Battery

Abstract

Li2ZnTi3O8 (LZTO) has been highlighted as a promising active anode material for rechargeable lithium-ion batteries, but it suffers from a low high-rate capacity due to the sluggish Li-ion diffusion kinetics and inevitable consumption of Li+ due to side reactions at the electrode/electrolyte interface. In this study, using Li3PO4 as a lithium ion conductor and interface modifier, the crystal structure and electrochemical properties of LZTO are systematically studied and confirm that it is a faster lithium ion conductivity. Li3PO4 not only accelerates Li-ion transport and increases diffusion paths, but also exhibits interfacial stability at high temperatures. Due to these advantages, the LZTO electrode containing the Li3PO4 coating layer exhibits significantly improved electrochemical performance. The new Li3PO4 coated LZTO electrode shows a large discharge specific capacity of 158.9 mAh g − 1 and a high capacity retention of 99% is obtained after 200 cycles at a rate of 5.0 A g − 1 and combined with cycle stability. Furthermore, the Li3PO4 coated LZTO electrode also exhibits excellent low electrode polarization and high temperature long cycling performance for 500 cycles at temperatures up to 70 °C.