Electric vehicles are becoming more popular every year, and better batteries are a big part of making them more affordable and practical.
One of the most promising new battery designs uses high levels of nickel while avoiding cobalt, a costly mineral that is difficult to source. These next-generation batteries can store more energy, giving electric cars a longer driving range at a lower cost.
However, new research from Hanyang University in South Korea has uncovered a surprising problem that could reduce the lifespan of these advanced batteries before they are even built.
The study, published in Energy and Environmental Science, shows that simply exposing battery materials to air during manufacturing can create hidden damage that speeds up battery wear over time.
The researchers focused on materials used to make high-nickel cathodes, one of the key parts of a lithium-ion battery. These cathodes often contain manganese, which is added to improve stability and protect the battery during use.
The team found that when the precursor materials used to make these cathodes are stored in areas where they are exposed to air, the manganese on the surface begins to react with oxygen. Although this change is very small and difficult to detect, it creates tiny defective areas in the material.
These hidden defects make the battery much more chemically active once it is in use. As the battery charges and discharges, the damaged surface can cause the battery’s liquid electrolyte to break down.
It also allows metal particles to dissolve and triggers harmful reactions with the battery’s graphite anode. Together, these problems make the battery lose its storage capacity much faster than expected.
According to the researchers, batteries made from air-exposed materials showed nearly twice the rate of capacity loss during long-term testing compared with batteries made under better-controlled conditions.
The good news is that the team also found a simple way to reduce the problem. By adding a little more lithium during the battery manufacturing process, they were able to prevent the defective surface from forming. This helped restore stable chemical bonds involving manganese and oxygen, making the cathode much more durable.
In laboratory tests, the improved batteries were able to keep more than 90% of their original capacity after extended use, a major improvement in long-term performance.
The findings suggest that manufacturers may not need expensive new coatings or major factory redesigns to build longer-lasting batteries. Instead, paying closer attention to how battery materials are stored before production and carefully adjusting the amount of lithium used during manufacturing could significantly improve battery durability.
The researchers say their work highlights an important lesson for the battery industry. Moving away from cobalt is an important goal, but understanding how other materials such as manganese behave during manufacturing is just as critical. Better control of these hidden chemical changes could help future electric vehicles travel farther, last longer, and provide more reliable energy storage for renewable power systems.
The study was conducted by researchers at Hanyang University in South Korea and was published in the journal Energy and Environmental Science.
Source: KSR.
