3D printing interdigital lithium-sulfur micro-batteries with high areal energy density

Internet of Things (IoT) and miniaturized devices have catalyzed the pursuit of progressive power systems characterized micro-size and high energy density. However, conventional batteries, typically adopting immobilized cylindrical or rectangular shapes, struggle to meet these demands. Herein, we propose a 3D printing strategy to build interdigital lithium-sulfur micro-batteries with enhanced areal energy density. By infusing lithium in 3D printed porous reduced graphene oxide architectures, dendrite-free lithium metal micro-electrodes in customized interdigital and spiral shapes are achieved. Lithium-symmetric micro-battery yields a remarkable 1200-hour lifetime and low overpotential (35 mV). Coupled with shape-matched sulfur micro-cathodes, the interdigital full batteries exhibit two times the areal energy densities of traditional lithium-ion batteries (7.58 mWh cm−2 vs. ∼ 3.0 mWh cm−2). This suggests the potential of 3D printed micro-batteries as promising power sources for on-chip electronic devices and integrated circuit.