Electrochemically Induced Crystallite Alignment of Lithium Manganese Oxide to Improve Lithium Insertion Kinetics for Dye-Sensitized Photorechargeable Batteries

Abstract

The insertion of lithium into lithium manganese oxide spinel (LiMn 2 O 4 (LMO) to Li 2 Mn 2 O 4 (L 2 MO)) was used to store light energy as a form of chemical energy in a dyesensitized photorechargeable battery (DSPB). Herein, we investigate the effect of crystallite size of LMO on DSPB performance. The crystallite size of graphene-wrapped submicrometer-sized LMO (LMO@Gn) was tuned electrochemically from 26 to 34 nm via repeated LMO-to-L 2 MO transitions. The different crystallite orientations in LMO@Gn particles were ordered in an identical direction by an electric stimulus. The LMO@Gn having a 34 nm crystallite size (L 34 and L 34* ) improved DSPB performances in dim light, compared with the smaller-crystallite LMO@Gn (L 26 ). The overall energy efficiency (η overall ) of 13.2%, higher than ever reported, was achieved by adopting the fully crystallized and structure-stabilized LMO@Gn (L 34* ) for DSPB. The phase transition between the cubic and tetragonal forms during the LMO-to-L 2 MO reaction was suspected to be responsible for the structural ordering.

Photoelectrochemical energy storage materials: design principles and functional devices towards direct solar to electrochemical energy storage

“…Hyun-Kon Song et al investigated the phase transition process during the insertion of lithium into LiMn 2 O 4 to form Li 2 Mn 2 O 4 in a dye-sensitized photoelectrode, and the photorechargeable battery could obtain an overall energy efficiency as high as 13.2%. 43 Wei Lv et al prepared a dye-sensitized TiO 2 –Cu 2 S composite and once illuminated with visible light, the generated dye + helps in the oxidation reaction during the process of charging and discharging. 44 Wan Jae Dong et al coated semiconducting polymers poly(3-hexylthiophene) (P3HT) on indium tin oxide branched nanowires (ITO BRs).…”

Influence of the Lithium-Ion Concentration in Electrolytes on the Performance of Dye-Sensitized Photorechargeable Batteries

“…Additionally, the properties of DSPBs under a high energy density remain unclear. The energy density of DSPBs is mainly determined by their output capacity ( Q out ) and output voltage ( V out ), which, in turn, depend on the following photocharge/discharge processes: ,− TiO 2 ( e − ) + LiMn 2 normalO 4 + Li + → TiO 2 + Li 2 Mn 2 normalO 4 Dye + + normalM red → Dye + normalM ox [Li-ion in the electrolytes diffuse from EL photo to EL storage . ][Li-ion in the electrolytes diffuse from EL storage to EL photo .…”

Non-destructive Monitoring of Dye Depth Profile in Mesoporous TiO2 Electrodes of Solar Cells with Micro-SORS

“…Dye-sensitized photon-to-electron conversion systems including dye-sensitized solar cells (DSSCs), dye-sensitized photo-rechargeable batteries, and dye-sensitized photo-electrochemical cells have been investigated as one of the most promising photo-electronic devices using outdoor light, and especially dim indoor light. − The dye distribution inside the semi-conducting layer is significantly influential for the device performance. For that reason, the state of dye distribution inside a titanium dioxide (TiO 2 ) film has been studied by several methods but prevalently based on destructive approaches − that are not suitable for monitoring the internal state of the devices under in-operando conditions.…”