[SMM Analysis: Battery technology iteration and renewal--How far is the future of lithium manganese iron phosphate? 】

At the end of March, it was reported that the filing of Jiangsu Qianyun-tech New Materials Co., Ltd.'s lithium iron manganese phosphate cathode material project (phase one, 100,000 tons) had been approved. Prior to this, several cathode material manufacturers had already set up production capacities for lithium iron manganese phosphate. Domestic material companies such as Ronbay Technology, Pulead Technology Industry, Advanced NanoTech Lab, and Hunan Yuneng, as well as international companies like Samsung SDI, LG Energy Solution, and SK On, have already laid out their strategies in this area.

In terms of production processes, lithium iron manganese phosphate is obtained by doping Mn into the LiFePO4 material, so the preparation process can continue down the same path as lithium iron phosphate, including solid-phase and liquid-phase methods. It only requires an additional source of manganese during the precursor preparation stage and a slight modification in kiln temperature and sintering process during the subsequent sintering phase. The rest of the steps are broadly similar. Both solid-phase and liquid-phase methods for lithium iron manganese phosphate can utilize the same equipment initially set up for lithium iron phosphate. Solid-phase methods include high-temperature solid-phase synthesis and carbothermal reduction, while liquid-phase methods encompass coprecipitation, sol-gel, and hydrothermal techniques.

The solid-phase method has a relatively simple process and is the mainstream method for large-scale synthesis. However, because raw materials are not easily mixed uniformly, it can lead to extended calcination times and uneven distribution of surface activity, resulting in uneven particles. The liquid-phase method yields products with high consistency, but the equipment and process are more complex, the preparation cost is higher, and large-scale industrial production is more challenging.

However, lithium iron phosphate is a semiconductor, and after doping with manganese, the bandgap value decreases significantly. Lithium iron manganese phosphate is basically an insulator with lower electronic conductivity and lithium-ion mobility, hindering the movement of electrons and lithium ions in electrochemical reactions, which directly limits its development and application. Nanosizing lithium iron manganese phosphate materials, surface coating, microstructural morphology control, and metal doping are all modification methods that can effectively improve their electrochemical activity and are the main challenges manufacturers currently need to overcome.

At present, the development path approved by companies is to mix lithium iron manganese phosphate with ternary cathode materials, which results in products that offer both safety and high energy density and allows for a range of solutions to flexibly meet end-user requirements. However, from an economic perspective, using lithium iron manganese phosphate alone is more economical. Still, it requires technological breakthroughs, and the economic advantages brought about by increased energy density will gradually become apparent.

In summary, lithium iron manganese phosphate has a higher energy density than lithium iron phosphate, and its costs are lower than the ternary materials, offering an energy density similar to that of ternary 5 series materials, but with higher safety, lower price, and environmental friendliness, making it one of the important directions for cathode material upgrades. The combination of lithium iron manganese phosphate and ternary materials yields products with both high safety and energy density, constituting the mainstream development path through a strong alliance.

Leading companies are also actively laying out strategies for the lithium iron manganese phosphate sector, with the industrialization process accelerating. There are various technological approaches, and some cathode material manufactures have sent samples for testing with battery cell manufacturers and automotive companies. It is expected that the pace of mass production will also accelerate.