UNIST scientists have previously introduced a PRB known as a dye-sensitized photorechargeable battery (DSPB) in a previous study. This battery has shown a high energy conversion and storage efficiency of 11.5% under indoor lighting.
In a new study, scientists developed a novel battery system that showed a high overall energy efficiency (ηoverall) of 13.2% under indoor lights. This is the highest overall efficiency of photorechargeable batteries (PRBs) ever reported under indoor lights.
In this study, scientists researched the impact of the crystallite size of LMO on DSPB performance. The crystallite size of graphene-wrapped submicrometer-sized LMO ([email protected]) was tuned electrochemically from 26 to 34 nm through repeated LMO-to-L2MO transitions. The different crystalline orientations in [email protected] particles were sequenced in an identical direction by an electric stimulus. The [email protected] having a 34 nm crystallite size (L34 and L34*) improved DSPB performances in dim light, contrasted and the more modest crystallite [email protected] (L26).
Scientists noted, “The findings demonstrate that the overall energy efficiency (ηoverall) of 13.2% was achieved by adopting the fully crystallized and structure-stabilized [email protected] (L34*) for DSPB. The phase transition between the cubic and tetragonal forms during the LMO-to-L2MO reaction was suspected to be responsible for the structural ordering.”
- Myeong-Hee Lee, Byung-Man Kim, Yeongdae Lee, et al., “Electrochemically Induced Crystallite Alignment of Lithium Manganese Oxide to Improve Lithium Insertion Kinetics for Dye-Sensitized Photorechargeable Batteries,” ACS Energy Letters. DOI: 10.1021/acsenergylett.0c02473