Low-Temperature Performance Analysis of Lithium Iron Phosphate Batteries

The performance of lithium iron phosphate batteries degrades significantly in low-temperature environments, with a capacity fade of 35% at -20℃. The main reason is that low temperatures inhibit the migration of electrolyte ions and reduce reaction activation efficiency. In low-temperature environments, the viscosity of the electrolyte increases, significantly increasing the migration resistance of lithium ions inside and at the interface of positive and negative electrode materials, which in turn leads to a sharp rise in battery internal resistance. Experimental data indicate that the capacity fades by 15% at -10℃ and 35% at -20℃. The capacity fade caused by low temperatures is reversible and can be restored to the nominal capacity after heating, which provides a theoretical basis for optimizing the thermal management of low-temperature batteries. One of the core reasons for the reduced cruising range of new energy vehicle owners in northern China during winter is the attenuation of battery performance at low temperatures.