铝掺杂锰酸锂正极材料制备及第一性原理研究

采用固相法制备出高纯度纳米LiAl0.25Mn1.75O4并用此制备成了半电池，对其进行充放电循环测试和阻抗测试，并与原始LiMn2O4的测试结果相比较。另采用基于密度泛函理论的第一原理方法，研究了掺铝锰酸锂LiAl0.25Mn1.75O4的能带结构、态密度和原子布居，实验与计算分析结果表明LiAl0.25Mn1.75O4在室温下0.01C放电时首次放电容量为124.8mAh/h，室温0.2C下50个循环周期后放电比容量保持率可达到83.6%；LiAl0.25Mn1.75O4的能带带隙为0.21eV，分态密度中Al-s轨道与O-s轨道在-20eV左右的明显杂化，均表明LiAl0.25Mn1.75O4材料具有高导电率、高结构稳定性、高比容量保持率的性能，这为推动锂离子电池锰酸锂正极材料的发展提供理论依据。

Preparation and First-principle studies of doped Al in LiMn2O4

High purity nanometer LiAl0.25Mn1.75O4 was prepared by solid phase method and used to fabricate half-cell. The charge-discharge cycle test and impedance test were performed on the half-cell, and the results were compared with the original LiMn2O4 test results. In addition, the energy band structure, density of states and atomic population of aluminum-doped lithium manganese oxide LiAl0.25Mn1.75O4 are studied by using the first principle method based on density functional theory. The experimental and calculated results show that the first discharge capacity of LiAl0.25Mn1.75O4 is 124.8 mAh/h at 0.01 C at room temperature, and the discharge specific capacity retention can reach 83.6% after 50 cycles at 0.2 C at room temperature. The band gap of LiAl0.25Mn1.75O4 is 0.21 eV, and Al-s orbit and O-s orbit at about -20eV in the partial density of states are obviously hybrid, indicating that LiAl0.25Mn1.75O4 material has high conductivity, high structural stability and high specific capacity retention rate. Thus, it provides theoretical basis for promoting the development of LiMn2O4 cathode materials for Li-ion batteries.