International. Scientists at Lawrence Berkeley National Laboratory have developed a conductive polymer coating, called HOS-PFM, that could enable more powerful and longer-lasting lithium-ion batteries for electric vehicles.
"The breakthrough opens up a new approach to developing EV batteries that are more affordable and easier to manufacture," said Gao Liu, a senior scientist in Berkeley Lab's Energy Technologies Area who led the material's development.
"The HOS-PFM coating conducts both electrons and ions at the same time. This ensures battery stability and high charge/discharge rates while improving battery life," Liu continued.
"The coating also shows promise as a battery adhesive that could extend the life of a lithium-ion battery from an average of 10 years to about 15 years," he added.
To demonstrate the superior conductive and adhesive properties of HOS-PFM, Liu and his team coated aluminum and silicon electrodes with HOS-PFM and tested its performance in a lithium-ion battery configuration.
Silicon and aluminum are promising electrode materials for lithium-ion batteries due to their potentially high energy storage capacity and lightweight profiles. But these cheap and abundant materials wear out quickly after multiple charge/discharge cycles.
During experiments at Advanced Light Source and Molecular Foundry, the researchers demonstrated that the HOS-PFM coating significantly prevents aluminum and silicon-based electrodes from degrading during battery cycling, while also offering high battery capacity for 300 cycles, a performance rate that is on par with today's state-of-the-art electrodes.
"The results are impressive because silicon-based lithium-ion cells typically last a limited number of charge/discharge cycles and a limited lifespan," Liu explained.
"The HOS-PFM coating could allow the use of electrodes containing up to 80% silicon. Such a high silicon content could increase the energy density of lithium-ion batteries by at least 30. And because silicon is cheaper than graphite, the standard material for electrodes today, cheaper batteries could significantly increase the availability of entry-level electric vehicles," Liu said.
Next, the team plans to work with companies to scale up HOS-PFM for mass manufacturing. The research was supported by DOE's Office of Vehicle Technologies. The Toyota Research Institute provided additional funding.
