Advantages and disadvantages of lithium iron manganese phosphate and lithium iron phosphate

Lithium iron phosphate is a lithium-ion battery electrode material with the chemical formula LiFePO4 (LFP for short), which is mainly used in various lithium-ion batteries . Lithium iron phosphate has an ordered and regular olivine-type structure, in which lithium ions have one-dimensional mobility. Reversible extraction and insertion during charge and discharge.

Lithium iron phosphate started early, and its technology is relatively mature. Its core advantages are low price, environmental friendliness, high safety performance, better structural stability and cycle performance. The disadvantage is poor low temperature performance and low energy density.

Lithium iron manganese phosphate belongs to the mixed product of lithium iron phosphate and lithium manganese phosphate, and has the same structure as lithium iron phosphate, both of which are ordered and regular olivine structure. Lithium iron manganese phosphate and lithium iron phosphate have the same advantages of low cost, high safety performance, high thermal stability, no spontaneous combustion during acupuncture and overcharge, long life, safety and no risk of explosion. It can be said that it has both lithium iron phosphate and lithium iron phosphate. The advantages of lithium manganese phosphate can also make up for the shortcomings of low energy density of lithium iron phosphate, so it is also known as "an upgraded version of lithium iron phosphate".

Comparison of parameters between lithium iron phosphate and lithium iron manganese phosphate

1. The battery has higher energy density and longer battery life .

The theoretical capacity of lithium iron manganese phosphate is the same as that of lithium iron phosphate, which is 170mAh/g; but the electrode potential of lithium manganese iron phosphate relative to Li/Li is 4.1V, which is much higher than 3.4V of lithium iron phosphate, and it is located in the organic electrolyte system. Compared with lithium iron phosphate, the stable electrochemical window is increased by 0.7V, and the platform voltage is increased by 20%, thereby promoting the energy density of lithium iron manganese phosphate from 578Wh/kg to 697Wh/kg under the same volume and mass.

2. Lower manufacturing cost.

The main difference between the amount of lithium iron manganese phosphate and lithium iron phosphate materials is the change in the amount of manganese source required. The lithium iron phosphate cathode per kWh requires 0.61kg iron source, while the lithium iron manganese phosphate cathode per kWh requires iron source 0.13kg + manganese Source 0.38kg.

Defects of Lithium Iron Manganese Phosphate

Compared with lithium iron manganese phosphate and lithium iron phosphate, lithium iron manganese phosphate has the following defects:

1. Lithium iron manganese phosphate has a short cycle life and poor charge and discharge capacity. Manganese is added to lithium iron manganese phosphate, and the dissolution of manganese will lead to shorter cycle life, poor charge-discharge capacity and life.

2. The low conductivity of lithium iron manganese phosphate makes it difficult to exert its capacity, and the side reaction with the electrolyte makes it difficult to exert the capacity of its material.

Lithium battery , lithium iron manganese phosphate cathode material battery represents the future development direction of the battery. It is the most ideal power battery ever invented. In the future, it will even become the cheapest power battery and one of the core products for the future development of the battery industry. Compared with other power batteries, it has incomparable advantages.