UK (Commonwealth Union) – Electrical vehicles (EVs), even though assumed to be a recent technology, have been around since the 1800s. The widespread use was hindered in most cases due to high initial costs, together with low efficiency and lack of charging points. This is likely to change with concern over the environment pollution and high energy prices prompting many to make the switch.
Scientists have discovered the irregular movement of lithium ions in next-generation battery materials may lower their capacity and obstruct their performance. Researchers, led by the University of Cambridge, monitored lithium ions inside a promising new battery material in real time.
The prior belief was that the mechanism by which lithium ions are retained in battery materials is constant across the individual active particles. However, the Cambridge researchers discovered that during the charge-discharge cycle, lithium storage was not constant. When the battery is about to complete the discharge cycle, the surfaces of the active fragments get saturated by lithium while their cores are lithium deficient. This leads to the loss of reusable lithium and lower capacity.
The study was funded by the Faraday Institution, that could bring about improvement in existing battery materials and increase the development of next-generation batteries.
EVs can play a key role in the transition to a zero-carbon economy. Most EVs currently being used are powered by lithium-ion batteries, because of their high energy density. The evaluation of light interaction with active particles during battery operations under a microscope, led the researchers to see distinct differences in lithium storage when the charge-discharge cycle in nickel-rich manganese cobalt oxide was occurring.
Co-first author Alice Merryweather, from Cambridge University’s Yusuf Hamied Department of Chemistry, said: “This is the first time that this non-uniformity in lithium storage has been directly observed in individual particles”, adding that real time techniques like this were vital to capture the moment as the battery is cycling.
