CAJ | 학술논문

分别运用Materials Studio软件的CASTEP和Morphology模块对磷酸铁锂( LiFePO4)的结构和晶形进行计算模拟研究,获得其优化构型、电子结构、晶体形貌、晶面面积和晶面相对生长速率等特征参数。研究结果表明,PBE方法的计算精度明显高于 CA-PZ方法,化合物中的 Fe—O配位键本质上是共价键。 LiFePO4的理论模拟晶形为柱状晶体,与其块状的实测晶体形貌存在较大差异,这归因于理论模拟晶形是LiFePO4在真空中的生长晶习,而非真实环境下的晶习。在LiFePO4的实际晶形中,(020)晶面拥有较大的面积,这与该晶面的原子排列方式和原子占有率密切相关。此外,表面活性剂和LiFePO4各特征晶面之间可形成大量C—H…O氢键,将晶粒有效地包覆起来,降低其生长速率,从而抑制LiFePO4晶粒长大。
분별운용Materials Studio연건적CASTEP화Morphology모괴대린산철리( LiFePO4)적결구화정형진행계산모의연구,획득기우화구형、전자결구、정체형모、정면면적화정면상대생장속솔등특정삼수。연구결과표명,PBE방법적계산정도명현고우 CA-PZ방법,화합물중적 Fe—O배위건본질상시공개건。 LiFePO4적이론모의정형위주상정체,여기괴상적실측정체형모존재교대차이,저귀인우이론모의정형시LiFePO4재진공중적생장정습,이비진실배경하적정습。재LiFePO4적실제정형중,(020)정면옹유교대적면적,저여해정면적원자배렬방식화원자점유솔밀절상관。차외,표면활성제화LiFePO4각특정정면지간가형성대량C—H…O경건,장정립유효지포복기래,강저기생장속솔,종이억제LiFePO4정립장대。
The geometric and electronic structures, crystal morphology, crystal facet area and the crystal facet relative growing velocity of LiFePO4 were theoretically investigated by the CASTEP and Morphology modules. The obtained results show that the PBE functional has better accuracy than CA-PZ functional. The Fe—O coordina-tion bonds are covalent in nature. Moreover, the simulated crystal morphology is columnar, which is obviously different from the experimental crystal morphology of flake. This is due to the calculated crystal morphology is the crystal habit of LiFePO4 under the vacuum condition, not in the actual environment. For the experimental mor-phology of LiFePO4, the area of the (0 2 0) crystal facet is large, which is closely related with the atomic ar-rangement and density on the crystal surface. Additionally, there are many C—H…O hydrogen bonds between surfactant and crystal facets of LiFePO4 , the crystallites are coated and their growing velocities slow down, and so the surfactant can control crystallite growth.