Development of Electric Vehicle Battery Materials with 'Price Down, Capacity Up 16%'

Ulsan National Institute of Science and Technology Campus Venture Develops First Cathode Material with Less Than 1% Cobalt and 98% Nickel

[Asia Economy Reporter Kim Bong-su] Domestic researchers have developed a material that can significantly reduce the price of electric vehicle batteries while increasing capacity by 16%.

Ulsan National Institute of Science and Technology (UNIST) announced on the 18th that SMLAB, an in-house venture founded by Professor Jae-pil Cho of the Department of Energy and Chemical Engineering, has developed cathode materials for electric vehicle batteries that reduce the expensive cobalt (Co) content to less than 1% and increase the nickel (Ni) content up to 98%.

The nickel (Ni) content is a key factor determining battery capacity, and this is the first time cathode materials with a nickel content raised to 98% have been developed. Cathode materials with nickel content above 80% (NCM, NCA) are commonly called "high-nickel materials." They have attracted attention in the battery industry because they minimize the use of expensive cobalt while delivering high capacity. The core technology is to maximize nickel content to extend driving range while improving lifespan characteristics, and SMLAB has raised the nickel content to 98%. Generally, when the nickel content increases by 1%, the capacity per 1kg of material increases by 2Ah (ampere-hours). Increasing nickel content from 90% to 98% raises capacity by 16Ah.

Professor Cho explained, "Considering that the amount of cathode material typically used in electric vehicle batteries is 100kg, the capacity increases by 1600Ah, which also extends the driving range," adding, "The actual achievable capacity of battery cells applying Ni98 cathode materials is expected to be 230Ah/kg."

While increasing battery capacity can reduce lifespan and stability, SMLAB improved these aspects by applying a new ceramic-based coating material. Currently commercialized high-nickel materials have nickel contents around 88-90%, and during cathode material synthesis, a washing process is required to remove lithium impurities remaining on the material surface by rinsing with water. However, during this washing process, a large amount of elements dissolve into the water, making it difficult to secure mass production quality. This is why three domestic battery manufacturers have theoretically suggested a maximum nickel content of 94% for mass production but have yet to develop it.

Another issue is that currently commercial cathode materials are in a "polycrystalline form," where very small particles are clustered together. Polycrystalline materials easily break during the rolling process, which is a manufacturing step where the cathode material-coated aluminum plate passes between rotating rolls to form a plate of uniform thickness. The breaking of polycrystalline materials during this process promotes unnecessary reactions inside the battery. This increases gas generation and affects charge-discharge cycles, thereby reducing lifespan. SMLAB significantly reduced these problems by producing cathode materials in a "single-crystal form."

The newly developed Ni98 NCMA single-crystal material contains less than 1% cobalt, the most expensive component, making it advantageous in terms of cost competitiveness. Typically, Ni90 cathode materials use more than 5% cobalt, increasing the price.

Professor Cho stated, "We succeeded in developing cathode materials with 98% nickel content two years ahead and plan to verify mass production in early 2022."

This content was produced with the assistance of AI translation services.