Porous Isomeric Li 2.5 Na 0.5 V 2 (PO 4 ) 3 Wide Voltage Cathode for High‐Performance Lithium‐Ion Batteries Synthesized Through a Colloid Chemical Method

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 Li 2.5 Na 0.5 V 2 (PO 4 ) 3 porous nanoparticle composite synthesized through a colloid chemical strategy. This composite is composed of monoclinic Li 3 V 2 (PO 4 ) 3 (M–LVP), rhombohedral Li 3 V 2 (PO 4 ) 3 (R‐LVP) and rhombohedral Na 3 V 2 (PO 4 ) 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.