What is a Quaternary Lithium Battery
With the rapid development of electric vehicles and large-scale energy storage systems, the demand for rechargeable batteries with high energy density has increased sharply. In order to meet the needs of high energy density, high safety attributes and cost reduction, people have been conducting extensive research on electrode materials. Today, let's learn about the new NCMA Quaternary lithium battery and see what advantages it has compared with the current ternary lithium battery.
At present, the mainstream ternary batteries in the market are roughly divided into two technical routes: NCA and NCM. However, whether NCA or NCM, consumers have the same demands for pure electric vehicle power batteries: improving safety, improving energy density and reducing costs. NCMA, intuitively, seems to be NCA + NCM.
In short, increasing the proportion of nickel in ternary lithium battery can improve the energy density of the battery, plug more power under the same weight, and make the car run farther. However, when the nickel content exceeds 90% (i.e. ultra-high nickel battery), the thermal stability of the battery will decline rapidly, and the capacity retention rate will also begin to decline. That is, the security is reduced and it is easier to decay. NCMA battery, on the basis of NCM ultra-high nickel battery, is mixed with aluminum. According to the research, the performance of NCMA battery is greatly improved.
Aluminum doping significantly improves the cycle stability of nickel rich NCM cathode, but it is accompanied by the loss of battery capacity when excessive introduction. Finally, the researchers put forward the most reasonable scheme, namely ncma89: Li [Ni 0.89 co 0.05 Mn 0.05 al 0.01] O 2, in which nickel accounts for 89%, cobalt accounts for 5%, manganese accounts for 5% and aluminum accounts for 1%. This battery provides the best combination of capacity and cycle life, and its performance is better than NCA and NCM batteries with similar positive nickel content, Li [Ni 0.90 co0.05 mn0.05] O2 (ncm90) and Li [Ni 0.885 co0.100 al0.015] O2 (nca89) were compared. As shown in the figure below, compared with NCA 89 and NCM 90 ultra-high nickel ternary batteries, NCMA 89 quaternary batteries perform better than NCA and NCM in six dimensions such as capacity attenuation and micro crack suppression.
For example, the capacity retention rates of NCMA 89, NCM 90 and NCA 89 are 84.5%, 68% and 60.2% respectively when 1000 charge discharge tests are carried out at 25 ℃, 3.0 - 4.2V and 1 C.
The thermal stability of the cathode is also important for battery safety. It can be seen from the scanning calorimetry data that the peak temperature of nca89 cathode exothermic reaction is 202 ° C and the heat generated is 1753 J G – 1, while the peak temperature of ncm90 cathode is 192 ° C and the heat generated is 1561 J G – 1. In contrast, the Peak Exothermic Temperature of ncma89 is 205 ° C and the heat generated is 1384 J G – 1, showing higher thermal stability. The improvement of the thermal performance of ncma89 cathode is attributed to the reduction of the number of microcracks, thereby reducing the number of permeable electrolytes. Because the synergistic action of Al, Al and Mn ions stabilizes the layered structure and delays the thermally induced phase transition, the ncma89 cathode is the most stable in structure.
However, the mass production process of quaternary lithium battery is more complex than ternary lithium battery, and it still takes a long way to achieve mass production.