With the rapid start of domestic lithium manganate LMO products this year, more and more industry insiders began to focus on this market. It is understood that because the price of NCM has been at a high level in the first half of the year, many manufacturers take LOM to reduce the material cost, and take LOM to adulterate NCM more often. At present, the common ones on the market vary from 9:1, 7:3, 8:2, 6:4 ratio, and the application market is different, for this reason, I take you to talk about those things of LMO and NCM.
At present, LMO is divided into three categories.
Laminated lithium manganate LiMnO2, theoretical capacity 285mA˙h/g, voltage platform 4V. Laminated structure is difficult to synthesize, unstable, very easy to generate Li2Mn2O4 spinel structure and lead to voltage platform decline, poor stability, irreversible capacity decay, etc.
High-pressure spinel LiMn2O4, theoretical capacity 148mA˙h/g, voltage platform 4.15. Poor high temperature performance, capacity decay above 55℃. It is also easy to generate Li2Mn2O4 spinel structure, which leads to the decrease of voltage platform, poor stability and irreversible decay of capacity, etc. Lithium manganate is currently used in industry.
Spinel lithium manganate Li2Mn2O4, low voltage (3V), low capacity, poor circulation, are studying how to avoid the generation of such things.
In terms of ternary materials.
In order to solve the defects of layered lithium manganate, through the method of doping metal elements, the invention of Ni, Co (Al) instead of manganese ternary materials LiNiCoMnO2 (LiNiCoAlO2), taking into account the high capacity and high voltage of lithium nickelate, lithium manganate high voltage and high security, lithium cobaltate good cycle, while overcoming the lithium manganate lithium nickelate synthesis is difficult and unstable, lithium cobaltate high cost It has become the mainstream cathode material at present. The theoretical capacity of 280mA˙h/g, voltage 2.7~4.2, now the actual capacity is about 160mA˙h/g.
LMO characteristics.
LMO has no precious metal, the price is relatively low; while NCM is trapped by high cobalt price, the price is high (high nickel material can reduce BOM cost, but the process cost increases).
LMO voltage platform is high, 3.75~3.8V, NCM voltage platform is low, 3.6~3.7V
LMO spinel structure, security is relatively good; NCM layer structure, easy lithium-nickel mixed row, security is poor (the higher the Ni% the worse)
The most critical gram capacity, LMO is lower and NCM is higher.
LMO high temperature performance is particularly poor, so the industrial use is LMO doped ternary. Typical as LMO: NCM = 7:3 (low cost, electric bicycle), 5:5or3:7, logistics vehicles
After adding LFP, the overall cost: pure LMO
More suitable for: ① cost sensitive; ② energy density has certain requirements; ③ safety requirements are not high in the field, such as electric bicycle, low-speed vehicles, etc.
At present, the spinel lithium manganate of a few domestic companies can already achieve nearly 1000 cycles, with a gram capacity of 115mAh/g, and the price is only more than 60,000 yuan per ton. Compared with ternary materials, the price advantage is outstanding, and in terms of multiplier, lithium manganate has been dominant, not to mention the safety, ternary doping manganese one is to reduce the cost, the second is to pass the safety test. However, the high temperature performance of lithium manganate is a problem, and the compaction of ternary is better than lithium manganate.
