3D printing of solid-state zinc-ion microbatteries with ultrahigh capacity and high reversibility for wearable integration design

Miniaturized and integrable energy storage systems (MI-ESSs) are highly desired to power portable and wearable electronics. Zinc-ion microbatteries (ZIMBs) are reliable MI-ESS candidates with excellent electrochemical potential; however, the viability and real application of conventional ZIMBs are long stricted by low device capacity/reversibility and challenging device package design. Herein, we report an all-3D-printing design of solid-state ultrahigh-capacity and highly reversible ZIMBs and achieve an advanced wearable integration. Calcium vanadate nanoribbon-based cathode and Zn nanosheet-based anode are rationally constructed by direct ink writing-based 3D printing. With a Cu-modification, dendrite-suppressed anode affords a low polarization and stable voltage profiles during long-term Zn plating/stripping. 3D printed solid-state ZIMBs deliver an outstanding device capacity of 8.9 mAh cm−2, which surpasses previously reported ZIMBs and even lithium-ion microbatteries. Superior rate capability and cycling stability is also achieved. By regulating 3D printing parameters, an ultrahigh device capacity reaches at 14.9 mAh cm−2. Furthermore, vat photopolymerization-enabled microbattery packaging is demonstrated as an efficient 3D printing platform to integrate ZIMBs into wearable monoliths. Such remarkable electrochemical behaviors and wearable integration applications are attributed to advanced 3D printing techniques and sophisticated microelectrode design, paving future roads in manufacturing of state-of-the-art MI-ESSs and powering portable and wearable electronics.