Boosting Low Temperature Performance of Lithium Ion Batteries at −40°С Using a Binary Surface Coated Li3V2(PO4)3 Cathode Material

Abstract Severe capacity degradation at low temperatures (<−20°С) hampers wide applications of lithium‐ion batteries (LIBs) in consumer electronics and electric vehicles. Existing works are dedicated to electrolyte modification because that electrolyte controls both Li + transportation and interfacial reaction. However, the efforts on electrolytes are always hard to balance rate performance and low‐temperature capacity due to their high viscosity. Herein, a binary coating layer for Li 3 V 2 (PO 4 ) 3 cathode material without changing electrolyte formulation is proposed, which significantly improves the high‐rate capability and low‐temperature performance of batteries. YPO 4 nanoparticles are in situ formed in the amorphous surface carbon layer under the reaction between Li 3 V 2 (PO 4 ) 3 and Y(NO 3 ) 3 during post‐thermal treatment. The C+YPO 4 binary coating reduces the side reactions of Li 3 V 2 (PO 4 ) 3 at high voltage. In addition, the binary surface coating also improves the interfacial kinetics of the electrode at low temperatures. Benefiting from these advantages, the Li 3 V 2 (PO 4 ) 3 cathode material can cycle stably at ultra‐high rates up to 50 C. In addition, the capacity retention at −20 and −40 °С are improved to 89.1% and 75.7%, respectively. This binary surface‐coated Li 3 V 2 (PO 4 ) 3 cathode material shows promising application potential in low‐temperature LIBs.