High‐Performance Packaged 3D Lithium‐Ion Microbatteries Fabricated Using Imprint Lithography

Abstract Fabrication of high‐energy‐density and high‐power‐density packaged long‐cycle‐life rechargeable microbatteries remains a considerable challenge. Here, high‐performance microbatteries with high active volume fraction, thick, 3D‐structured electrodes (V 2 O 5 cathode and Li metal anode) are realized through a combination of imprint lithography, self‐assembly, and electrodeposition. To assist the critical challenge of hermetic packaging, the microbattery is infilled with a gel electrolyte. The packaged cell exhibits high areal energy and power densities of 1.24 J cm −2 and 75.5 mW cm −2 , respectively, and can be cycled 550 times in argon or 200 times in air with 75% capacity retention of the initial discharge capacity. An unpackaged cell, using a liquid electrolyte, provides a power density of 218 mW cm −2 . As far as it is known, the microbatteries have the highest peak power density among all reported microbatteries.