INFLUENCE OF CARBON CONDUCTING ADDITIVES ON THE PERFORMANCE OF SI/C COMPOSITE ANODES FOR LITHIUM BATTERIES

摘要

Most of commercial lithium-ion batteries are based on a graphite anode. In standard conditions, lithium can reversibly intercalate in graphite to form the compound LiC6. The ratio limits the capacity to 372 mAh/g [1], but in a real cell the capacity very rarely exceeds 350 mAh/g [2]. Disordered carbons were claimed to demonstrate a higher reversible capacity than graphite but a large irreversible lithium trapping after the first charge cycle is a serious drawback of the materials [3]. Silicon with a theoretical capacity of 4235 mAh/g is a very attractive anodic material, however, huge swelling (up to 300%), poor electric conductivity and, in consequence, a noticeable capacity loss during cycling make difficult to apply pure silicon as anode.