LiFePO₄ is an attractive cathode material for lithium ion battery due to its high capacity of 170 mAh g⁻¹, long cycle life, good safety and low cost, which suffers from the instinct low electron conductivity and poor rate performance. Herein, a composite material consisting of LiFePO_4, activated carbon and graphene is synthesized with a facile solvothermal method, which presents excellent high-rate performance with highly-efficiency capacitive-battery characteristics. The obtained LiFePO₄/activated carbon/graphene cathode material has hierarchical porous architecture mainly originated from the activated carbon and interconnected conductive networks constructed by the graphene, ensuring both the abundant pathways for Li⁺ diffusion and the fast electron transfer. Furthermore, the high surface area (367 m² g⁻¹) provides a double layer capacitive process during charge/discharge process, and also protects the LiFePO₄ against the heavy current attack, especially under high current rate. As a result, the capacitive-battery behavior leads to superior rate capability and long cycle life. The LiFePO₄/activated carbon/graphene cathode exhibits a remarkable high capacity of 66 mAh g⁻¹ at an extremely high rate of 100 C, and the brilliant cycle stability is confirmed with the capacity retention of 82% after 3000 cycles, promising the high power applications. Furthermore, this study provides a new insight in simple preparation of the capacitive-battery materials by combing the active components and the capacitive components.

LiFePO ₄由于其170 mAh g ^-1的高容量，长循环寿命，良好的安全性和低成本而成为锂离子电池的有吸引力的正极材料，其遭受本能的低电子电导率和差的倍率性能。在此，通过简便的溶剂热法合成了由LiFePO _4，活性炭和石墨烯组成的复合材料，该复合材料具有优异的高倍率性能和高效的电容电池特性。所获得的LiFePO ₄ /活性炭/石墨烯正极材料具有分层的多孔结构，主要来源于活性炭和由石墨烯构成的相互连接的导电网络，从而确保了Li ⁺的丰富途径扩散和快速电子转移。此外，高表面积（367 m ²  g ^-1）在充电/放电过程中提供了双层电容性过程，并且还保护了LiFePO ₄免受大电流冲击，特别是在高电流速率下。结果，电容电池的行为导致了优异的速率能力和长循环寿命。LiFePO ₄ /活性炭/石墨烯阴极表现出显着的高容量，为66 mAh g ^-1在100 C的极高速率下，经过3000次循环后其容量保持率达到82％，从而证实了出色的循环稳定性，这有望在高功率应用中得到应用。此外，这项研究通过组合有源组件和电容组件，为电容电池材料的简单制备提供了新的见解。