Nanocrystalline Titanium Dioxide for Solar Cells and Lithium Batteries

1 Results Nanocrystalline TiO2 (anatase) has attracted considerable interest for applications in regenerative photoelectrochemical solar cells[1]. This device is based on charge injection from photoexcited organometallic dye which is adsorbed on the TiO2 surface. A considerable enhancement of the solar cell efficiency was demonstrated on highly organized mesoporous TiO2 thin films made by supramolecular templating with amphiphilic triblock copolymer Pluronic[2]. Titanium dioxide can electrochemically accommodate Li which is useful for a design of new Li-ion batteries. Whereas the charge storage in anatase or rutile is based on the Li-insertion into the bulk crystal lattice, the monoclinic TiO2(B) exhibits an unusual pseudocapacitive Li-storage mechanism[3]. Photo(electro)chemical studies were carried out employing various forms of TiO2 ranging from single-crystal electrodes[4] towards polycrystalline mesoscopic films, either from randomly distributed nanocrystals[1] or from organized framework nanotextures[2]. As expected the photoelectrochemical and Li-insertion activity of mesoscopic TiO2 depend significantly on the electrode morphology. Salient features of Ti(Ⅳ) oxide electrodes will be reviewed for the applications in solar cells and Li-ion batteries.