Use of sacrificial lithium nickel oxide for loading graphitic anode in Li-ion capacitors

The use of non-stoichiometric lithium nickel oxide, being a part of the activated carbon positive electrode in lithium-ion capacitors, is presented as an alternative to the use of metallic lithium for graphite pre-lithiation. During the first cycle, lithium ions are irreversibly extracted from the Li0.65Ni1.35O2 host structure and intercalated into the graphite negative electrode. Once extraction and pre-lithiation are completed, activated carbon becomes the only active material for electrical double-layer storage at the positive electrode, while reversible lithium intercalation occurs at the graphite negative one. Since the lithium ions extraction occurs at a potential of 4.2 V vs. Li/Li+, electrolyte oxidation is prevented, and the cell displays a good cyclability in the potential range from 2.2 V to 3.8 V.