A theoretical evaluation of the effect of interlayer spacing and boron doping on lithium storage in graphite

Using first-principles computations, we investigated the effect of the graphite interlayer spacing and substitutional boron doping on the storage capacity of Li ions. We found that increasing the distance between graphite layers only moderately increases the capacity because of a combination of geometric and electronic effects. Doping with boron results in a noticeable increase in the saturation Li intercalation density by about 33.3% at boron contents of BC15 and BC7 with regard to the pristine graphite predicts that the maximum of saturation Li intercalation density locates at around 10 at% of boron content. The electronic structures of Li-intercalated graphite systems were analyzed to explain these effects.