废旧磷酸铁锂正极材料修复再生的研究

Research on the Cathode Regeneration Technology of Waste Lithium Iron Phosphate Batteries

正极磷酸铁锂(LiFePO_(4))材料结构稳定,而活性锂的损失是电池容量衰减的主要原因之一。通过先除杂、补充元素,再经过高温煅烧对废旧LiFePO4进行再生修复。SEM、XRD和电化学性能测试结果表明:在600℃煅烧20小时条件下,除杂质碳的效果最佳;利用水热反应补充元素并高温煅烧修复后的LiFePO_(4)粒径更小更均匀;制备的电池在2.8~4.0V进行充放电测试,在0.2C,循环130圈时的比容量达151mAh g^(-1),容量保持率为89%,库伦效率保持率为96%;0.5C、1C及2C放电比容量最高分别达115 mAh g^(-1)、93 mAh g^(-1)、68 mAh g^(-1)。

The anode lithium iron phosphate(LiFePO 4)material is structurally stable,and the loss of active lithium is one of the main causes of battery capacity degradation.The results of SEM,XRD and electrochemical performance tests show that the best effect of carbon removal was achieved by calcination at 600℃ for 20 h.The particle size of LiFePO_(4) repaired by hydrothermal reaction and high-temperature calcination was smaller and more uniform.In charge and discharge tests,the specific capacity reached 151 mAh g^(-1) at 0.2C and 130 cycles,with 89%capacity retention and 96%Coulomb efficiency retention;the highest specific capacity reached 115 mAh g^(-1),93 mAh g^(-1) and 68 mAh g^(-1) at 0.5C,1C and 2C respectively.