Porous Isomeric Li_2.5Na_0.5V₂(PO₄)₃ Wide Voltage Cathode for High‐Performance Lithium‐Ion Batteries Synthesized Through a Colloid Chemical Method

Abstract

The synthesis of highly active and stable cathode materials for lithium‐ion batteries (LIBs) is a major challenge for electrochemical energy storage. Herein, we report an isomeric Li2.5Na0.5V2(PO4)3 porous nanoparticle composite synthesized through a colloid chemical strategy. This composite is composed of monoclinic Li3V2(PO4)3 (M–LVP), rhombohedral Li3V2(PO4)3 (R‐LVP) and rhombohedral Na3V2(PO4)3 (R‐NVP). Benefiting from the porous structure and synergistic effects between the stable M−LVP and highly conductive R‐LVP, this composite cathode exhibits outstanding electrochemical performance for LIBs. It shows a high discharge capacity of 228.1 mAh g−1 at 0.1 C rate (1 C=150 mA g−1) and 108.9 mAh g−1 at 10 C rate in a wide potential range between 1.5 and 4.3 V. Moreover, even in a high current density of 10 C, it still exhibits a stable cycle performance and retains a discharge capacity of 80 mAh g−1 after 500 cycles.