Introduction of lithium manganese oxide development prospects
There are many types of lithium-ion batteries, and different types of batteries use different cathode materials, resulting in differentiation. In this article, I will introduce the advantages, disadvantages and applications of lithium manganese oxide cathode materials, as well as the main preparation methods.
What is lithium manganese oxide
The chemical formula of lithium manganese oxide is LiMn2O4, which has a cubic spinel crystal structure and contains three lithium ion transport channels in space. Therefore, compared with other positive electrode materials, the lithium manganese oxide cathode material has a higher ion diffusion rate and is suitable for lithium-ion batteries that require high-rate charging.
Lithium manganese oxide is one of the more promising lithium ion cathode materials. The spinel type lithium manganese oxide belongs to the cubic crystal system, Fd3m space group, and the theoretical specific capacity is 148mAh/g.
Due to the three-dimensional tunnel structure, lithium ions can be reversibly deintercalated from the spinel lattice without causing the collapse of the structure, resulting in excellent rate capability and stability.
What does lithium manganese oxide do
Mainly used in the manufacture of lithium-ion batteries for mobile phones, notebook computers and other portable electronic devices as positive electrode materials. The main use of lithium manganese oxide is new energy batteries, and other uses include electric tools, electric toys and other energy storage tools that need to be moved. Lithium manganese oxide ion battery spare parts for pneumatic tools, medical equipment, and hybrid and new energy vehicles.
Advantages and disadvantages of lithium manganese oxide
Lithium manganese oxide is said to be a spinel structure, which refers to its crystal shape applied to lithium batteries. When lithium manganese oxide is not applied to lithium batteries, there is also a layered structure.
Relatively speaking, the spinel structure is more stable than the layered structure (although based on chemical properties, it seems that the stability of different shapes in geometry can also be thought of), so the spinel structure is still used in practical applications.
In addition to lithium manganese oxide, lithium cobalt oxide and ternary lithium battery positive electrodes also have a spinel structure, but the spinel structure of lithium manganese oxide is very distinctive compared with its two counterparts.
● Manganese reserves are abundant, so the battery cost can be greatly reduced, which is conducive to mass industrial production and application;
● Battery made of LiMn2O4 cathode is safe, resistant to overcharge discharge, even without protection circuit; good rate performance, low temperature resistance.
● Manganese is non-toxic and non-polluting, and the solution to its recycling problem has accumulated rich experience in primary batteries, so the use of LiMn2O4 cathode materials is beneficial to environmental protection.
the material itself is unstable and needs to be mixed with other materials, poor high temperature performance, poor cycle performance, and fast attenuation.
These disadvantages of lithium manganese oxide arise from the properties of manganese. However, due to the widespread presence of manganese, it has a clear cost advantage.
The main preparation methods of lithium manganese oxide
There are currently six preparation methods for lithium manganese oxide, which are divided into high-temperature solid-phase method, melt impregnation method, microwave synthesis method, hydrothermal synthesis method, co-precipitation method, and sol-gel method.
Among them, the main lithium manganese oxide on the market today has two types: AB, and type A refers to the materials used for power batteries, and its characteristics are mainly considering safety and recycling. Class B refers to the substitutes of mobile phone batteries, which are mainly characterized by high capacity.
① The basic technological process of high-temperature solid-phase method is: mixing → roasting → grinding → screening → product. The solid-phase method has the advantages of simple operation process, mass production and low cost.
② The melt impregnation method refers to a better method in the preparation of spinel-type lithium manganese oxide by the solid-state method.
Anode materials with excellent electrochemical performance can be obtained, but due to complicated operation and harsh conditions, it is not conducive to industrialization.
③ The microwave synthesis method is obviously different from the traditional high-temperature solid-phase method in the synthesis of materials. The method is used to prepare materials with excellent electrochemical properties, and the synthesis reaction time can be greatly shortened.
④ Hydrothermal synthesis LiMn2O4, a positive electrode material for lithium-ion batteries synthesized by hydrothermal synthesis, the crystal structure is stable and the crystal state is uniform, so the synthesized material has excellent physical and electrochemical properties.
⑤ The lithium-ion battery material prepared by co-precipitation method not only has higher electrochemical capacity and longer cycle life, but also has the advantages of simple process, easy operation and fast reaction speed.
⑥ The sol-gel method is actually a branch of the co-precipitation method. The LiMn2O4 produced has excellent physical and electrochemical properties, but it is not conducive to industrial production due to problems such as high cost.
lithium manganese oxide vs other lithium batteries material
Compared with traditional cathode materials such as lithium cobalt oxide, lithium manganese oxide has the advantages of abundant resources, low cost, no pollution, good safety, and good rate performance.
It is an ideal cathode material for power batteries, but its poor cycle performance and electrochemical stability greatly limit its industrialization. Secondly, compared with ternary lithium battery/lithium iron phosphate batteries, lithium manganese oxide batteries have the advantage of being cheaper. The temporary problem is the number of cycles. He has several super-booming application scenarios.
The use environment of electric two-wheeled vehicles is harsher than that of automobiles, and the probability of wading and collision is higher than that of automobiles. In economic considerations, the cost of battery packs should not be too high.
Compared with ternary lithium materials, lithium manganese oxide is cheaper and safer. Compared with iron-lithium materials, lithium manganese oxide will not lose power so easily in winter low temperature conditions, and the charging performance remains the same. But now there are lithium iron phosphate batteries for low temperature, but the cost is also high. In the end lithium manganese oxide became one of the good choices.
According to statistics, the share of lithium manganese oxide batteries in two-wheeler lithium batteries was 42% in 19 years, 45% in 20 years, and 56% in 21 years.
Development prospects of lithium manganese oxide
According to statistics, in China’s current manganese consumption structure, 85%-90% is used in the steel industry, and about 5%-10% is used in the battery industry and chemical industry. In recent years, the rapid development of green manufacturing industries such as new materials and electric vehicles will provide a broad market for cathode materials such as electrolytic manganese dioxide, lithium manganate and high-purity manganese sulfate.
China’s cathode material shipments were 510,000 tons, of which lithium manganate shipments were 66,000 tons, accounting for 13%. Although affected by the epidemic in the first half of the year, the demand for low-end digital batteries and exports to other countries has decreased, but the demand for electric two-wheeled vehicle batteries that began to erupt during the epidemic has supported the lithium manganate market.
China’s lithium manganate output reached 92,900 tons, a year-on-year increase of 21.6%, and is expected to reach 109,000 tons. At present, there are more than 40 Chinese lithium manganate cathode material companies in the lithium manganese oxide industry, and 90% of the production capacity is generally below 10,000 tons. There is a shortage of leading enterprises, and industry integration is just around the corner.