Abstract
Delithiation followed by lithiation of Li(+)-occupied (n-type) tetrahedral sites of cubic LiMn(2)O(4) spinel (LMO) at ~4 [Formula: see text] (delivering ~100 mAh g(LMO)(-1)) has been used for energy storage by lithium ion batteries (LIBs). In this work, we utilized unoccupied (p-type) octahedral sites of LMO available for lithiation at ~3 [Formula: see text] (delivering additional ~100 mAh g(LMO)(-1)) that have never been used for LIBs in full-cell configuration. The whole capacity of amphi-redox LMO, including both oxidizable n-type and reducible p-type redox sites, at ~200 mAh g(LMO)(-1) was realized by using the reactions both at 4 [Formula: see text] and 3 [Formula: see text]. Durable reversibility of the 3 V reaction was achieved by graphene-wrapping LMO nanoparticles (LMO@Gn). Prelithiated graphite (Li(n)C(6), n < 1) was used as anodes to lithiate the unoccupied octahedral sites of LMO for the 3 V reaction.