Improvement of battery performance by applying iron-containing recycled aluminum to current collector-free anode of lithium-ion batteries

Lithium-ion batteries with graphite anode have been utilized in a condition close to the theoretical capacity of graphite, and thus the application of current collector-free aluminum anode has been attempted for further increase in capacity because theoretical capacity of aluminum is 2.7 times larger than that of graphite. In this study, Al-2mass%Fe alloy was applied as a noble anode material, and found to possess better discharge capacity retention and Coulomb efficiency than those of 4N-purity aluminum. Such improvement of battery performance in Al-2mass%Fe anode is attributed to the formation of more stable reaction layers of randomly oriented nanocrystalline AlLi owing to finely dispersed intermetallic compounds of Al6Fe and Al3Fe. This result would expand application ranges of recycled aluminum containing larger amounts of impurity iron, with less future demand from foundry industries to be partly compensated.