氧化硼修饰的钴酸锂材料及其电化学性能

The effect of B_(2)O_(3) modification on the electrochemical properties of LiCoO_(2) cathode

钴酸锂材料由于具有高的能量密度、优异的倍率性能和热稳定性被广泛应用于各种消费类电子产品,随着人工智能和5G时代的到来,人们对钴酸锂电池的能量密度有了更高的需求。本研究通过利用简单的固相法对钴酸锂进行硼化物包覆,经过改性后的钴酸锂材料(BLCO)相比于未改性的原始材料(LCO)电阻率下降一个数量级,该材料组装成的电池在常温下3~4.55 V的初始容量达到201.2 mAh/g,高于原始钴酸锂材料的192.64 mAh/g,循环500周后容量为194.8 mAh/g,高于原始材料的184.37 mAh/g。这种提升是由于硼化物改性后的钴酸锂材料具有更高的电子电导率和更小的界面阻抗,本工作提供了一种提升高电压钴酸锂材料容量的方法并对高电压下钴酸锂材料的失效机制进行了初步分析,对未来高容量钴酸锂材料的设计具有较大参考意义。

Lithium cobalt oxide is widely employed in different consumer electronic products due to its high energy density,rate performance,and thermal stability.With the advancement of artificial intelligence and 5G communication technology.A higher energy density of LiCoO_(2)(LCO)batteries is required.In this study,lithium cobalt oxide was coated with B_(2)O_(3) using the simple solid-state approach.The resistance of B_(2)O_(3) modified LiCoO_(2)(BLCO)was much lower than the pristine LiCoO_(2)(LCO).The discharge capacity of BLCO at 3-4.55 V and room temperature reach 201.2 mAh/g,which was greater than 192.64 mAh/g of the pure LCO.The capacity retention of BLCO after 500 cycles was 194.8 mAh/g,which was higher than 184.37 mAh/g of the pristine LCO.This enhancement can be attributed to the higher electronic conductivity and smaller interface impedance of BLCO.Our research provides a method to enhance the capacity of lithium cobalt oxide.The failure mechanism of lithium cobalt oxide material cycled at high voltage was also investigated,which will be helpful for the design of high voltage lithium cobalt oxide in the future.