An Enhanced Extend Interface via the π–π Interaction to Achieve the Soluble Light‐Assisted Lithium–Oxygen Batteries

Abstract The light‐assisted strategy is considered as an effective way to reduce the overpotential of lithium‐oxygen (Li─O 2 ) batteries, however, the generated solid discharge products are prone to cover active sites of the solid‐state photocatalyst, causing the premature death of the cell. Herein, for the first time, the feasibility of soluble photocatalysts in Li─O 2 battery system using Iron (II) Phthalocyanine (FePc) is verified. A micro reaction channel is constructed between the sp 2 ‐carbon cathode and the soluble photocatalyst‐phthalein iron through π–π interaction, which can effectively increase the three‐phase reaction interface, facilitating the rapid separation and the transportation of photogenerated electrons and holes, thus improving the photocatalytic efficiency and the reaction kinetics of Li─O 2 battery. Moreover, the FePc soluble photocatalysts induced the dual growth modes of surface growth and solution‐mediated growth pathways for the discharge products lead to an additional discharge capacity in the Li─O 2 battery. Accordingly, the battery exhibits a lower overpotential of 0.33 V between discharge and charge plateaus at a current density of 0.01 mA cm −2 , displaying the excellent cyclic stability (remaining a round‐trip efficiency of 81.1% after 130 cycles). The novel strategy provides new approaches for the construction of the light‐assisted Li─O 2 batteries with reduced overpotential and boosted energy efficiency.