Lithium-ion batteries are used in smartphones, laptops, electric cars, and stationary energy storage systems. Although their design has hardly changed in years, one key problem remains: the gradual aging of cells. That’s why lithium-ion batteries lose capacity over time.
A team of researchers at the University of Maryland (via NewScientist) have discovered a new solution that could extend the service life of lithium-ion batteries, all without changing internal cell structure or existing production processes.
Why do lithium-ion batteries age?
Every lithium-ion battery consists of two electrodes: a negative anode and a positive cathode. Between them is a liquid electrolyte through which lithium ions migrate when charging and discharging. Over time, this electrolyte deteriorates and the byproducts are deposited as extremely thin layers on the electrodes.
This byproduct effect is actually desirable on the anode, where it forms a stable layer that protects the electrode from further wear and tear, making the battery more durable. Unfortunately, not so for the cathode, which operates under highly oxidizing conditions and doesn’t form a comparable protective layer. Thus, aging and deterioration.
How the new solution works
The team, led by materials scientist Chunsheng Wang, investigated a new approach that doesn’t tweak the electrodes but rather the electrolyte in between. Inspired by known reactions from organic chemistry, they adjusted its properties so that ion transfers are more controlled.
The effect is that the electrolyte no longer deteriorates randomly but in a controlled manner, forming a uniform and stable protective layer on the cathode, which slows down further degradation. Crucially, no exotic materials are required for this. According to the researchers, it uses chemicals and processes already used in the battery industry.
Another advantage of this process is its flexibility. The composition of the protective layer on the cathode can be varied. A thicker layer increases stability and extends the battery’s service life but slows down ion transport, while a thinner layer allows for higher power and energy densities but results in faster wear.
This would allow batteries to be tailored to their specific application—for example, maximum durability in stationary energy storage systems or maximum performance in electric vehicles.
What does this mean for you?
It remains to be seen how much this new solution will actually extend the service life of lithium-ion batteries. The technology is in an early testing phase and reliable long-term data isn’t yet available.
Nevertheless, experts are optimistic about it. Energy storage expert Michel Armand from Spanish research center CIC energiGUNE described the controlled formation of a protective layer on the cathode as an important step towards longer-lasting batteries.
For consumers, nothing will change in the short term. In the medium-to-long term, however, this solution could help batteries in everyday devices retain capacity and improve longevity without manufacturers having to develop completely new cell types.
Further reading: Is it bad to leave your laptop always plugged in?
