Aleksis Rihards, Nedumkandathil Reji, Papawassiliou Wassilios, Carvalho José P, Jaworski Aleksander, Häussermann Ulrich, Pell Andrew J
Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden.
Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga, LV 1006, Latvia.
Phys Chem Chem Phys. 2022 Nov 30;24(46):28164-28173. doi: 10.1039/d2cp04675j.
Perovskite-type oxhydrides such as BaTiOH exhibit mixed hydride ion and electron conduction and are an attractive class of materials for developing energy storage devices. However, the underlying mechanism of electric conductivity and its relation to the composition of the material remains unclear. Here we report detailed insights into the hydride local environment, the electronic structure and hydride conduction dynamics of barium titanium oxyhydride. We demonstrate that DFT-assisted solid-state NMR is an excellent tool for differentiating between the different feasible electronic structures in these solids. Our results indicate that upon reduction of BaTiO the introduced electrons are delocalized among all Ti atoms forming a bandstate. Furthermore, each vacated anion site is reoccupied by at most a single hydride, or else remains vacant. This single occupied bandstate structure persists at different hydrogen concentrations ( = 0.13-0.31) and a wide range of temperatures (∼100-300 K).
钙钛矿型氢氧化物，如BaTiOH，具有混合的氢负离子和电子传导特性，是开发储能装置的一类有吸引力的材料。然而，其导电的潜在机制及其与材料组成的关系仍不清楚。在此，我们报告了对氢氧钡钛矿的氢化物局部环境、电子结构和氢化物传导动力学的详细见解。我们证明，DFT辅助的固态核磁共振是区分这些固体中不同可行电子结构的优秀工具。我们的结果表明，在BaTiO还原时，引入的电子在所有Ti原子之间离域形成一个能带态。此外，每个空出的阴离子位点最多被一个氢化物重新占据，否则保持空位。这种单占据能带态结构在不同的氢浓度（= 0.13 - 0.31）和很宽的温度范围（~100 - 300 K）下都持续存在。
