Researchers at the US Department of Energy’s (DOE) Argonne National Laboratory have reported that a new photo-excitation mechanism can speed up the charging of lithium-ion batteries by a factor of two or more. An open-access paper on their work appears in Nature Communications . A serious limitation [of lithium-ion batteries], however, is the slow charging rate used to obtain the full capacity. Thus far, there have been no ways to increase the charging rate without losses in energy density and electrochemical performance. Here we show that the charging rate of a cathode can be dramatically increased via interaction with white light. We find that a direct exposure of light to an operating LiMn 2 O 4 cathode during charging leads to a remarkable lowering of the battery charging time by a factor of two or more. This enhancement is enabled by the induction of a microsecond long-lived charge separated […]