Patent attributes
Provided is method of improving fast-chargeability of a lithium secondary battery, wherein the method comprises disposing a lithium ion reservoir between an anode and a porous separator and configured to receive lithium ions from the cathode through the porous separator when the battery is charged and to enable the lithium ions to enter the anode in a time-delayed manner. In some embodiments, the reservoir comprises a conducting porous framework structure having pores and lithium-capturing groups residing in the pores, wherein the lithium-capturing groups are selected from (a) redox forming species that reversibly form a redox pair with a lithium ion; (b) electron-donating groups interspaced between non-electron-donating groups; (c) anions and cations wherein the anions are more mobile than the cations; or (d) chemical reducing groups that partially reduce lithium ions from Li+1 to Li+δ, wherein 0<δ<1.
