LiMnPO₄ (LMP) is known as a typical cathode for application in lithium-ion-batteries (LIB), since this cathode produces higher voltage. However, the diffusivity of Li⁺ into LMP crystalline structure is not sufficiently high and its application accompanies a large energy waste due to hysteresis loss in the charge-discharge cycle. Therefore, in this work, it is intended to show that partial substitution of Mn with Fe, as a dopant to obtain a crystal with a general formula of Li_xMn_1−zFe_zPO₄ for application as a cathode in LIB, not only can increase the diffusivity of Li⁺ but also can improve other electrochemical properties of the resulting crystal, as a cathode, compared with pristine LMP or with similar cathodes such as LiFePO₄ (LFP). To study the properties of this cathode, a multiscale procedure consisting of quantum mechanical (QM) approach at picoscale level and by recourse to density functional theory (DFT) calculations along with molecular dynamics(MD) simulation at the nanoscale level as well as pseudo-two-dimensional (P2D) electrochemical model at the macroscale level, the parameters affecting the performance of LIBs due to employing the cathodes LMP, LFP, and Li_xMn_0.75Fe_0.25PO₄ (LMFP) are investigated and the obtained results, in comparison with the available experimental data are validated, justified, and interpreted. It is found that the cathode LMFP, if used as a cathode in a LIB, would results in higher efficiency and lower voltage drop compared with the commonly used cathode LMP as well as producing higher voltage power in comparison to LFP.

LiMnPO ₄（LMP）被称为锂离子电池（LIB）中的典型阴极，因为该阴极产生更高的电压。然而，Li ⁺到LMP晶体结构的扩散率不够高，并且由于充放电循环中的磁滞损耗，其应用伴随着大量的能量浪费。因此，在这项工作中，意图是表明用掺杂剂Fe部分取代Mn，以获得通式为Li _x Mn _{1- z} Fe _z PO ₄的晶体，而不是将其用作LIB中的阴极。只能增加Li ⁺的扩散率与原始LMP或类似的阴极如LiFePO ₄（LFP）相比，它还可以改善所得晶体作为阴极的其他电化学性能。为了研究该阴极的特性，采用了多尺度程序，该过程包括皮克级的量子力学（QM）方法，求助于密度泛函理论（DFT）的计算以及纳米级的分子动力学（MD）模拟以及伪模拟。二维（P2D）电化学模型的宏观水平，由于使用阴极LMP，LFP和Li _x Mn _0.75 Fe _0.25 PO ₄而影响LIB性能的参数（LMFP）进行了调查，并与可用的实验数据进行了比较，验证和解释所获得的结果。已经发现，如果将阴极LMFP用作LIB中的阴极，则与常用的阴极LMP相比，其将导致更高的效率和更低的电压降，并且与LFP相比，将产生更高的电压功率。