Researchers at Lawrence Berkeley National Laboratory (Berkeley Lab) have devised a conductive polymer coating called HOS-PFM that can offer longer-lasting, more robust lithium-ion batteries for electric vehicles.
The advance opens up a new approach to developing EV batteries that are more affordable and easy to manufacture.
Gao Liu, Senior Scientist, Energy Technologies Area, Lawrence Berkeley National Laboratory
Gao Liu guided the development of the material.
The HOS-PFM coating conducts electrons and ions concurrently. This improves battery life by ensuring battery stability and high charge/discharge rates. The coating also shows great promise as a battery adhesive, potentially extending the lifetime of a lithium-ion battery from 10 to 15 years, according to Liu.
Liu and his colleagues coated aluminum and silicon electrodes with HOS-PFM and evaluated their effectiveness in a lithium-ion battery setup to demonstrate HOS-PFM’s conductive and adhesive properties.
Due to their potentially high energy storage capacity and lightweight profiles, silicon and aluminum are enticing electrode materials for lithium-ion batteries. However, after multiple charge/discharge cycles, these inexpensive and abundant materials quickly deteriorate.
The findings reveal that the HOS-PFM coating substantially inhibits silicon- and aluminum-based electrodes from degrading during battery cycling while providing superior battery capacity over 300 cycles during experiments at the Advanced Light Source and the Molecular Foundry.
According to Liu, the findings are remarkable since silicon-based lithium-ion cells typically have a limited number of charge/discharge cycles and calendar life. These findings were published in the journal Nature Energy.
The HOS-PFM coating may enable the use of electrodes containing up to 80% silicon. According to Liu, such a high silicon content could improve the energy density of lithium-ion batteries by at least 30%. Furthermore, because silicon is less expensive than graphite, the current standard material for electrodes, lower-cost batteries could substantially increase the availability of entry-level electric vehicles, he added.
The team will collaborate with companies to scale up HOS-PFM for mass production.
The study was funded by DOE Vehicle Technologies Office. Additional funding was offered by the Toyota Research Institute.
Journal Reference
Zhu, T., et al. (2023) Formation of hierarchically ordered structures in conductive polymers to enhance the performances of lithium-ion batteries. Nature Energy. doi.org/10.1038/s41560-022-01176-6.