Photochromic Molybdate for Advancing Anode Capacity of Lithium‐Ion Battery

Photochromic polyoxomolybdate is first used to enhance the anode capacity and rate performance of Li‐ion batteries. Abstract Decoupling strategies can effectively enhance lithium‐ion battery (LIB) capacity, but suffer from the need for complex equipment, preventing widespread applicability. This work offers, for the first time, a decoupling strategy of electron‐transfer photochromism to improve LIB anode performance, without requiring complex equipment. The approach utilizes a new crystalline photochromic molybdate, MV[Mo9O28] (1, MV = methyl viologen cation) as the LIB anode. After UV irradiation, the initial 1 undergoes electron transfer from O to Mo, accompanied by a color change from colorless to blue and the generation of an ultra‐stable charge‐separated state with a lifetime of up to 2 years under ambient conditions. The observed capacity increases by 132 ± 14 mAh· g−1 across various current densities after coloration, along with superior rate performance—retaining 7.6% more capacity than the initial state even at a 100‐fold higher current density. Theoretical calculations confirm that the enhanced capacity and rate performance are attributable to the stable charge‐separated state. This unprecedented photochromic charge‐separated strategy contributes to the exploration of new outstanding anode materials for LIBs. Photochromic polyoxomolybdate is first used to enhance the anode capacity and rate performance of Li-ion batteries. Abstract Decoupling strategies can effectively enhance lithium-ion battery (LIB) capacity, but suffer from the need for complex equipment, preventing widespread applicability. This work offers, for the first time, a decoupling strategy of electron-transfer photochromism to improve LIB anode performance, without requiring complex equipment. The approach utilizes a new crystalline photochromic molybdate, MV[Mo 9 O 28 ] ( 1, MV = methyl viologen cation) as the LIB anode. After UV irradiation, the initial 1 undergoes electron transfer from O to Mo, accompanied by a color change from colorless to blue and the generation of an ultra-stable charge-separated state with a lifetime of up to 2 years under ambient conditions. The observed capacity increases by 132 ± 14 mAh· g −1 across various current densities after coloration, along with superior rate performance—retaining 7.6% more capacity than the initial state even at a 100-fold higher current density. Theoretical calculations confirm that the enhanced capacity and rate performance are attributable to the stable charge-separated state. This unprecedented photochromic charge-separated strategy contributes to the exploration of new outstanding anode materials for LIBs. Advanced Science, EarlyView.