Electrochemical Performance of LiFePO₄ Cathode with Dispersed Ion-Conductive Material

Abstract

Lithium-ion batteries (LIBs) with LiFePO 4 (LFP) cathodes have gained significant commercial traction due to their high energy density, excellent rate capabilities, and cost-effectiveness. However, meeting the demand for high-power and high-energy-density storage presents challenges. This study introduces garnet Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 (LLZTO) integration at nano and micro scales in a well-dispersed suspension, enhancing lithium-ion transport without compromising mechanical strength. LFP-nano-LLZTO-dispersant exhibits improved physical and electrical performance, attributed to smooth surfaces influenced by dispersant addition. Assembly of Li-cells resulted in notable capacity retention for LFP-nano-LLZTO-dispersant, increasing from 79.1% to 94.5% at a 0.5 C rate after 300 cycles, with a reversible capacity of 72.1 mA h g −1 . Furthermore, the incorporation of LFP-micro/LLZTO-dispersant demonstrated enhanced electrochemical performance, with stable high-capacity retention rising from 89.6% to 98.6% and a reversible capacity of 136.4 mA h g −1 after 300 cycles at 0.5 C. This improvement is attributed to the use of micro-sized garnet LLZTO particles and suitable dispersant, which prevent cathode cracking, reduce electrolyte degradation into too thick formation of cathode electrode interface (CEI) layer, and enhance LFP electrode cycle stability. Figure 1