Expensive Process Eliminated: Two Carbon Powders Boost Electric Vehicle Battery Capacity by 20%

[Financial News] A technology has been developed that can simultaneously increase battery capacity and charging speed simply by mixing existing battery-material powders, without expensive advanced equipment or complex chemical processes. When combined with materials used in actual electric vehicle batteries and tested as a finished product, the technology increased the amount of energy that could be stored at once by more than 20% and improved charging speed by 14% compared with conventional batteries.
Korea University (KU) announced on the 7th that a research team led by Professor Young Soo Yoon of the KU-KIST Graduate School of Convergence Science and Technology, with master's student Kim Si-on as first author, significantly improved performance by physically mixing graphite and hard carbon, both anode materials for lithium-ion batteries. The team combined the mixed anode with NCM811, a leading cathode material for electric vehicles, and evaluated it in a complete battery. Compared with a conventional graphite battery, the resulting battery showed a 21.8% increase in energy density and a 14% increase in power density, which indicates how quickly a battery can deliver power or charge.
The technology is considered highly valuable economically because it can be readily applied at manufacturing sites. Typically, improving battery performance requires synthesizing expensive new materials or carrying out complex coating processes, which significantly raises production costs. In contrast, the research team used a conventional method of mixing two commercially available carbon powders as they are. This opens a path to improving performance without modifying existing battery production equipment.
The principle lies in the mutually complementary effect of the two materials. Graphite, which is widely used today, can store electricity stably for a long time. However, during fast charging at places such as highway rest stops, it may fail to accept lithium quickly enough, causing storage capacity to drop sharply or creating a risk of fire. Hard carbon, on the other hand, performs well during fast charging but has the limitation of stopping charging prematurely.
When the team mixed the two powders, graphite opened the way for hard carbon to be fully charged, while hard carbon reduced the current burden concentrated on graphite during fast charging. In this way, the two materials offset each other's weaknesses.
The experiments showed that the composite anode mixed at the optimal ratio delivered a high capacity of about 500 milliampere-hours per gram (mAh/g) under standard charging conditions. Even under ultra-fast charging, in which current was applied 16 times faster than usual, it stably maintained a capacity of 351 mAh/g.
The study, conducted with support from the National Research Foundation of Korea (NRF), was published in the international materials science journal Advanced Functional Materials.  

[email protected] Man-gi Kim Reporter