Enhancing low temperature properties through nano-structured lithium iron phosphate and solid liquid interface control by LATP

Abstract

Lithium iron phosphate battery works harder and lose the vast majority of energy and capacity at the temperature below -20 ℃, because electron transfer resistance (Rct) increases at low-temperature lithium-ion batteries, and lithium-ion batteries can hardly charge at -10℃. Serious performance attenuation limits its application in cold environments. In this paper, according to the dynamic characteristics of charge and discharge of lithium-ion battery system, the structure of lithium iron phosphate is adjusted, and the nano-size has a significant impact on the low-temperature discharge performance. The primary particle size of the material synthesized by the hydrothermal method is about 140 nm, and the discharge capacity under -20 ℃ is 93% than that of the capacity discharged under 25 ℃. The conductivity is in connection with the concentration of the electrolyte, and the application of highly concentrated liquid electrolyte and the addition of lithium-ion conductive material Li_1.3Al_0.3Ti_1.7 (PO₄)₃(LATP) in the positive electrode, the discharge capacity is more than 50% at ultra-low temperature -60℃ compares to the capacity released at 25℃.