碳布用于锂离子电池三维一体化柔性正极的可行性研究

Feasibility study of carbon cloth for 3D integrated flexible cathode of lithium-ion battery

研究碳纤维编织布用于锂离子电池三维一体化正极的可行性,对三种经过热处理碳布的石墨化程度进行定性分析和定量计算。以锂金属作为对电极,石墨化的碳布电极在0.1~0.5 V的电压下首次放电比容量分别为83.6,94.5mAh·g^(-1)和115.2 mAh·g^(-1),经过50周次循环充放电后比容量分别为55.0,80.0 mAh·g^(-1)和88.0 mAh·g^(-1)左右。将石墨化的碳布负载LiFePO_(4)后,电极的首次放电比容量分别为73.2,109.5 mAh·g^(-1)和130.2 mAh·g^(-1)。对于石墨化程度为76.02%的碳布,经过50周次循环充放电后比容量稳定在90.0 mAh·g^(-1)左右,综合电化学性能较好,更适合用于锂离子电池的一体化柔性正极。通过建立LiFePO_(4)颗粒与碳纤维之间相互作用的力学模型,探讨一体化正极的力学性能、电学性能和电化学性能之间的关系。将碳布用于锂离子电池一体化正极,可以简化锂离子电池的常规生产过程,革新其生产方式。

The carbon cloths made of carbon fiber as 3D integrated cathode for lithium-ion batterie were studied.The graphitization degree of three types of carbon cloths after heat treatment were qualitatively analyzed and quantitatively calculated.Using lithium metal as the counter electrode,the graphitized carbon cloth electrodes show first discharge specific capacities of 83.6,94.5 mAh·g^(-1)and 115.2 mAh·g^(-1)under 0.1-0.5 V,respectively.After 50 cycles,the specific capacities of carbon cloth electrodes remain 55.0,80.0 mAh·g^(-1)and 88.0 mAh·g^(-1).With LiFePO_(4)-loaded graphitized carbon cloths as cathodes,the initial discharge specific capacities of electrodes are 73.2,109.5 mAh·g^(-1)and 130.2 mAh·g^(-1),respectively.The carbon cloth whose graphitization degree is 76.02%shows stable specific capacity of about 90.0 mAh·g^(-1)after 50 cycles,and shows better comprehensive performances.This carbon cloth is more suitable for the integrated flexible cathode of lithium-ion batteries.By establishing the mechanical model of the interaction between LiFePO_(4)particles and carbon fiber,the relationship between mechanical,electrical and electrochemical properties of the integrated cathode were discussed.Using carbon cloth as an integrated cathode for lithium-ion batteries can simplify the conventional production process and innovate its production process.