Design and 3D Printing of Interdigitated Electrode Structures for High-performance Full Lithium-ion Battery

The tradeoff between energy and power densities is a critical challenge for commercial tape-cast lithium-ion batteries (LIBs). In this study, three-dimensional (3D) LIBs with interdigitated electrode structures are designed and fabricated via 3D printing to overcome this tradeoff. The evolution of battery design from tape-cast thin planar electrodes to interdigitated 3D electrodes is discussed. Numerical simulations based on COMSOL Multiphysics are performed to elucidate the advantages of interdigitated battery design. Interdigitated LIBs composed of comb-like 3D high-voltage LiCoO₂ (HV-LCO) cathodes and comb-like 3D natural graphite anodes are fabricated via 3D printing. Additionally, printable HV-LCO inks with appropriate rheological properties are developed for 3D printing. HV-LCO half-cells with Li foil as the counter electrode and an interdigitated full battery with NG anodes as the counter electrode are assembled to test the electrochemical performance. The results show that interdigitated full batteries fabricated via 3D printing offer high specific capacities and stable cycling performance. Full batteries with an electrode thickness of 882 µm can achieve a high areal capacity of 5.88 mAh·cm⁻² @ 0.1 C, an areal energy density of 41.4 J·cm⁻², and an areal power density of 41.0 mW·cm⁻² @ 1.0 C, which are approximately 10 times the values afforded by conventional tape-cast thin batteries.