Owing to the outstanding electrochemical performance,the LiFePO4 power batteries could be used on electric vehicles and hybrid electric vehicles.A kind of LiFePO4 power batteries,Cylindrical 26650,was manufactured from commercialized LiFePO4,graphite and electrolyte.To get batteries with good high-current performance,the optimal content of conductive agent was studied and determined at 8%of mass fraction.The electrochemical properties of lhe batteries were investigated.The batteries had high discharging voltage platform and capacity even at high discharge current.When discharged at 30 C current.they could give out 91.1%of rated capacity.Moreover,they could be fast charged to 80%of rated capacity in ten minutes.The capacity retention rate after 2 000 cycles at 1 C current was 79.9%.Discharge tests at-20℃and 45℃ also showed impressive performance.The battery voltage,resistance and capacity varied little after vibration test.Through the safetytests of nail,no inflammation or explosion occurred.%磷酸铁锂电池的优异性能使其可以应用在电动汽车和混合动力汽车上.用市售磷酸铁锂、石墨和电解液制作了圆柱型26650磷酸铁锂动力电池.为改善电池的大电流性能,研究了正极导电剂的最佳质量分数为8%.研究了所制备的动力电池的充放电性能.电池在高倍率下放电仍有较高的电压平台和放电容量.30 C(96 A)放电时,可放出额定容量的91.1%.电池大电流充电性能较好,5C(16 A)充电10 min左右,可充入额定容量的80%.1 C充放电循环2 000次,仍能保持额定容量的79.9%.高低温下电池放电性能良好.电池经过振动测试,内阻、电压和容量变化很小.针刺实验中没有发生起火和爆炸,电池温度峰值为94.7 ℃.
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