Metalized Polymer Current Collector for High‐Energy Lithium‐Ion Batteries with Extreme Fast‐Charging Capability

Electric vehicles are pivotal in the global shift toward decarbonizing road transport, with lithium‐ion batteries at the heart of this technological evolution. However, the pursuit of batteries capable of extremely fast charging that also satisfy high energy and safety criteria, poses a significant challenge to current lithium‐ion batteries technologies. Additionally, the increasing demand for aluminum (Al) and copper (Cu) in electrification, solar energy technologies, and vehicle light‐eighting is driving these metals toward near‐critical status in the medium term. This study introduces metalized polythylene terephthalate (mPET) polymer films by depositing an Al or Cu thin layer onto two sides of a polyethylene terephthalate film—named mPET/Al and mPET/Cu, as lightweight, cost‐effective alternatives to traditional metal current collectors in lithium‐ion batteries. We have fabricated current collectors that significantly reduce weight (by 73%), thickness (by 33%), and cost (by 85%) compared with traditional metal foil counterparts. These advancements have the potential to enhance energy density to 280 Wh kg −1 at the electrode level under 10‐min charging at 6 C. Through testing, including a novel extremely fast charging protocol across various C‐rates and long‐term cycling (up to 1000 cycles) in different cell configurations, the superior performance of these metalized polymer films has been demonstrated. Notably, mPET/Cu and mPET/Al films exhibited comparable capacities to conventional cells under extremely fast charging, with the mPET cells showing a 27% improvement in energy density at 6 C and maintaining significant energy density after 1000 cycles. This study underscores the potential of mPET films to revolutionize the roll‐to‐roll battery manufacturing process and significantly advance the performance metrics of lithium‐ion batteries in electric vehicles applications.