Heat treatment conditions of polyparaphenylene-based carbon for negative electrode of lithium ion secondary batteries

摘要

A high value of discharge capacity for the negative electrode of Li ion secondary battery, 554mAh/g at second cycle, was obtained using a polyparaphenylene (PPP)-based carbon material heat-treated at 720℃. The PPP is a kind of low crystalline carbon material. Li ion charge and discharge capacities of low crystalline carbon are thought to depend strongly on the resistance and the microstructure of the material. In order to clarify the effect of heat-treatment on the characteristics of PPP-based carbon as a negative electrode in the temperature range from 680 to 900℃, electrical and structural characteristics were investigated by means of charge-discharge capacity and resistivity measurement, field emission scanning electron microscopy and high resolution transmission electron microscopy and image analysis.