Electrochemical performance of hybrid-structured LiFe(PO4)0.5(BO3)0.5 cathode material for Li-ion batteries

Considerable efforts have been made to improve the electrochemical properties of complex-structured cathode materials for Li-ion batteries (LIBs), such as high specific capacity, good rate capability, and high energy density, enabling their future use in hybrid and electric vehicles (HEV/EVs). This communication reports for the first-time hybrid-structured LiFe(PO4)0.5(BO3)0.5 (LFBP) as a cathode material that exhibits a remarkably high specific discharge capacity 189.8 mAh g−1 at 0.1 C of near the theoretical capacity (98.8%, 192 mAh g−1). X-ray diffraction and nuclear magnetic resonance spectroscopy of the pristine material revealed a mixed phase of olivine and vonsenite structures. The electrochemical performance of the LFBP showed polymorphism with two different kinds of structured materials. Cyclic voltammetry and dQ/dV analyses also confirmed the activation of both the olivine LiFePO4 (LFP) and monoclinic LiFeBO3 (LFB) after the first cycle. The LFBP hybrid material demonstrated good electrochemical performance with a wide range operating voltage of 0.9 to 4.5 V required for a parallel Li-ion battery system for future energy storage systems.