摘要
采用基于密度泛函理论的第一性原理计算方法,研究贵金属Pt掺杂的正极材料Li_2Pt_(0.125)Co_(0.875)SiO_4在锂离子脱嵌过程中晶格和电子结构的变化.计算结果表明,掺杂体系在脱嵌锂离子过程中,晶格参数和体积变化不大,充放电过程中循环稳定性保持较好,脱嵌电压也基本保持不变;Li-O键长增大,Li-O间相互作用减弱,锂离子迁移率增大.与纯相Li_2CoSiO_4相比,禁带中出现了掺杂原子Pt的d轨道电子,带隙变窄,从而提高了掺杂材料Li_2Pt_(0.125)Co_(0.875)SiO_4的电子导电性.
First- principles studies based on the density functional theory have been carried out to investigate the changes of the lattice and electronic structure in the charging- discharging process for Pt- doped Li_2Pt_（0.125）Co_（0.875）SiO_4. The calculation results show that the changes of the lattice parameter and volume are marginal in the process of removing Li ions,which indicates that Pt- doped Li_2Pt_（0.125）Co_（0.875）SiO_4has high cycling stability and the average voltage also remain unchanged. And,Li- O bond length increases,then the interaction between Li- O decreases,which indicates that the lithium ion mobility increases. Compared with pure Li_2CoSiO_4,d orbital electrons of doped atom Pt emerge in the band gap,yielding narrower band gap,and the electronic conductivity of the Pt- doped Li_2Pt_（0.125）Co_（0.875）SiO_4is increased.
出处
《福州大学学报（自然科学版）》
CAS
北大核心
2015年第6期828-833,838,共7页
Journal of Fuzhou University(Natural Science Edition)
基金
国家自然科学基金青年科学基金资助项目(11404060)
