<p>➀ Fraunhofer FEP developed a roll-to-roll production method to create metal-polymer current collectors, replacing conventional metal foils with polymer substrates coated in copper/aluminum layers, improving battery energy density and safety;</p><p>➁ The novel collectors interrupt current flow during short circuits by melting the polymer layer, preventing thermal runaway, and use gas-cooled rollers for heat management during high-speed processing;</p><p>➂ Prototype pouch cells with these collectors matched traditional cells in performance tests, demonstrating industrial feasibility for next-gen lithium-ion batteries.</p>