Invited
NOVEL 3D-MICROBATTERIES ON 3D-PRINTED POLYMER SUBSTRATES

The absence of effective miniature power sources producing micro-watts of steady-state power with peaks to tens mW, is a hinder of the advance in smart self-powered IoT, wireless sensor networks, wearable devices for healthcare, and medical implants. Insufficient energy from thin-film planar (2D) batteries inspires the search for the three dimensional microbatteries (3DMB) using cheap and efficient micro-/nano-fabrication materials and techniques.

The exclusive capabilities of the 3D printing technology enable design of different shapes and high-surface-area structures, which no other manufacturing method can do easily. We present novel quasi-solid rechargeable 3D-microbattery assembled on the 3D-printed perforated polymer substrate (3DBPS). The interconnected channels formed through XYZ planes provide up to two orders of magnitude area gain of the substrate, available to the active battery materials as compared to planar batteries. We wish to point out that the novel structure simplifies electrochemical insertion of consecutive battery layers which, in turn, facilitates fabrication of 3D microbatteries with an aspect ratio much higher than 10. The battery occupies a footprint area of only a few mm², while its height may approach a few cm. Simple and inexpensive electrophoretic-deposition routes are applied for the fabrication of all the thin-film active-material layers of the microbattery. Taking advantage of thin films, which conformally follow all the contours of the 3D-substrate and are composed of nanosize electrode materials, like modified LFP, NCA, LTO, and original polymer-in-ceramic electrolyte, our 3D microbatteries offer high reversible specific capacity, high pulse power capability, and intrinsic safety.

Acknowledgements

The research is supported by the Israel Ministry of Science, Technology and Space