An innovative polymer coating pioneered by researchers at Lawrence Berkeley National Laboratory has been demonstrated to boost electric car battery life by up to 15 years.
The global uptake of electric vehicles (EVs) will be essential to decarbonising the transport sector and achieving net zero targets. However, a current limitation of the technology is their insufficient driving range and the short lifespan of their batteries. Scientists have potentially developed a revolutionary solution to these issues, designing a polymer coating called HOS-PFM that enhances electric vehicle battery power and lifespan.
Gao Liu, a senior scientist in Berkeley Lab’s Energy Technologies Area, explained: “The advance opens up a new approach to developing EV batteries that are more affordable and easy to manufacture.”
The research, ‘Formation of hierarchically ordered structures in conductive polymers to enhance the performances of lithium-ion batteries,’ may represent a significant milestone in e-mobility.
Electric car battery design must be advanced
The demand for electric cars is growing considerably each year, as major nations in the automotive space, such as the UK and US, have outlawed the sale of new petrol and diesel-power vehicles from 2035.
However, for EVs to be fully embraced by motorists around the world, various aspects of the technology will need to improve, including charging infrastructure, range capabilities, and electric car battery life.
Currently, the average driving range of an electric car is between 150-300 miles on a full charge, and the average life expectancy is around 15 to 20 years. These capabilities fall short of conventional cars and will need to improve in the coming years to drive the transition to electrified transport.
How does the new polymer coating work?
The HOS-PFM polymer coating works by conducting electrons and ions simultaneously, which ensures electric car battery stability and high charge/discharge rates while boosting battery life.
HOS-PFM has also demonstrated potential as a battery adhesive that could potentially increase lithium-ion battery lifetime for between ten to 15 years.
The team showed HOS-PFM’s exceptional conductive and adhesive properties by coating aluminium and silicon electrodes with the polymer coating – testing their performance on a lithium-ion battery set-up.
Aluminium and silicon are promising lithium-ion battery electrode materials due to their high energy storage capacity, abundance, lightweight and low cost. However, these materials break down after multiple charge/discharge cycles.
The team’s experiment showed that HOS-PFM prevents degradation in silicon- and aluminium-based electrodes during battery cycling. Simultaneously, the coating produced a high battery capacity of over 300 cycles – which is comparable to the performance of current state-of-the-art electrodes.
Liu concluded: “The results are impressive because silicon-based lithium-ion cells typically last for a limited number of charge/discharge cycles and calendar life.
“The HOS-PFM coating could allow the use of electrodes containing as much as 80% silicon. Such high silicon content could increase the energy density of lithium-ion batteries by at least 30%.
“Because silicon is cheaper than graphite, the standard material for electrodes today, cheaper batteries could significantly increase the availability of entry-level electric vehicles.”
