Multi-core-shell-structured LiFePO4@Na3V2(PO4)3@C composite for enhanced low-temperature performance of lithium-ion batteries

In this work, a multi-core-shell-structured LiFePO4@Na3V2(PO4)(3)@C (LFP@NVP@C) composite was successfully designed and prepared to address inferior low-temperature performance of LiFePO4 cathode for lithium-ion batteries. Transmission electron microscopy (TEM) confirms the inner NVP and outer carbon layers co-existed on the surface of LFP particle. When evaluated at low-temperature operation, LFP@NVP@C composite exhibits an evidently enhanced electrochemical performance in term of higher capacity and lower polarization, compared with LFP@C. Even at - 10 degrees C with 0.5C, LFP@NVP@C delivers a discharge capacity of ca. 96.9 mAh center dot g(-1) and discharge voltage of ca. 3.3 V, which is attributed to the beneficial contribution of NVP coating. NASICON-structured NVP with an open framework for readily insertion/desertion of Li+ will effectively reduce the polarization for the electrochemical reactions of the designed LFP@NVP@C composite.

Automated summary

A multi-core-shell-structured LiFePO4@Na3V2(PO4)(3)@C composite was successfully designed and prepared to improve the low-temperature performance of LiFePO4 cathode for lithium-ion batteries. The addition of NVP coating in the composite significantly enhanced the electrochemical performance, providing higher capacity and lower polarization even at -10 degrees C. The NASICON-structured NVP effectively reduced polarization for the electrochemical reactions, contributing to the improved performance of LFP@NVP@C composite.