Mechanical Structuring of Lithium-Ion Battery Electrodes Using an Embossing Roller

Abstract

Highly performing lithium-ion batteries are essential for the electrification of the transport sector. However, the two performance criteria, high power density and high energy density, inversely correlate with each other via the mass loading of the electrodes. To achieve high charging and discharging rates at high energy densities, structuring of electrodes is a proven method. Currently, structures are mostly realized by laser ablation, which comes along with material loss and low process rates. Herein, a concept for electrode structuring through mechanical embossing in a high-throughput roll-to-roll process is elaborated. Different integration options are described and the challenges are discussed. To provide a proof of concept, a hand-operated embossing device is built and used to structure graphite anodes. In a rate capability test, an increase in discharge capacity at medium C-rates by up to 14.3% is observed.