To realize the high value–added utilization of acid-washed iron red, in this paper, acid-washed iron red is used as raw material. Aiming at the problem of low conductivity of iron-based lithium ion batteries (LIBs) LiFePO₄/C materials, different metal ions are doped in the iron position, and the microstructure and electrochemical properties of the obtained material are systematically studied. Here, LiFePO₄/C is synthesized through simple carbothermal reduction method using acid-washed iron red as the iron source. On this basis, La (1%, 2%, 3%) doping modification is carried out. Then doped modification is performed on this basis, preferably 2% La-doped LiFePO₄/C materials. The XRD patterns show that the diffraction peaks of the samples prepared at all doping amounts can be perfectly matched with the standard card ( PDF # 40–1499), and there is no impurity peak, all of which are pure phases. According to the refined data, it is clear that minor amount of La has successfully replaced the position of Fe and incorporated into the lattice. Electrochemical tests show that LiFe_0.98La_0.02PO₄/C has the highest charge and discharge capacity of 146.5/138.2 mAh·g⁻¹ in the first cycle at 0.5C, and the reversible specific capacity of 136.5 mAh·g⁻¹ remains after 50 cycles. Furthermore, the first-principles calculations more strongly confirm that La doping can significantly improve the defects of low electronic conductivity of LiFePO₄.

为了实现酸洗铁红的高附加值利用，本文以酸洗铁红为原料。针对铁基锂离子电池（LIBs）LiFePO ₄ /C材料电导率低的问题，在铁位掺杂不同的金属离子，系统研究了所得材料的微观结构和电化学性能。在此，使用酸洗铁红作为铁源，通过简单的碳热还原法合成了LiFePO _{4 /C。}在此基础上进行La(1%、2%、3%)掺杂改性。然后在此基础上进行掺杂改性，优选2%La掺杂的LiFePO ₄ /C材料。XRD图谱表明，所有掺杂量制备的样品的衍射峰均能与标准卡（PDF#40-1499）完美匹配，且不存在杂质峰，均为纯相。根据精化数据，很明显少量的La已经成功取代了Fe的位置并融入到晶格中。电化学测试表明，LiFe _0.98 La _0.02 PO ₄ /C在0.5C下首次循环充放电容量最高，为146.5/138.2 mAh·g ^-1 ，循环后仍保持136.5 mAh·g ^-1的可逆比容量。 50 个周期。此外，第一性原理计算更加有力地证实了La掺杂可以显着改善LiFePO ₄电子电导率低的缺陷。