INVESTIGATION OF CONFINED LITHIA AS CATHODE FOR HIGH-ENERGY LITHIUM ION BATTERY

摘要

The capacity of traditional Li ion battery is too low to satisfy thernincreasing demand of energy density. Though Li Sulfur and Li-airrnbatteries have higher energy densities above 1000 mWhg~(-1), we canrnhardly promote them into industry because of the poor cyclingrnperformances and high over-potential. In this work, we come up to arntotally innovated idea that most discharge states of traditional electrodernand the cathode of Li-air battery can be considered as some specificrnmodification of Li_2O. Hereby, we directly used Li_2O as cathode withrnamorphous Co_3O_4 confinement (Fig a) in a sealed coin battery andrninvestigated its electrochemical performance. Results in Fig brnindicated that the confined Li_2O has an actual reversible capacity ofrn598 mAhg~(-1) under 120 mAg~(-1) so that the actual energy density exceedsrn1450 mWhg~(-1). The capacity retention of Li_2O is 97% after 100 cycles.rnAdditionally, the voltage gap between charge and discharge is onlyrn0.25 V, 80% reduced compared to Li-air battery due to the catalysis ofrnamorphous Co_3O_4 shell. Analysis implies that no O_2 generation andrnelectrolyte decomposition have been detected during the batteryrnprocess.