Acupuncture-Inspired Active-Material Microenvironment Engineering for High-Throughput Thick Electrodes by Instant Microneedle Templating.

Abstract

Rational design and ultrafast fabrication of high-throughput thick electrodes are essential for high-energy and power density batteries. However, it is blocked by the lack of both theory and cost-effective technologies for regulating the active-material microenvironment (AMME) that fundamentally controls the ion and electron transport for each active-material particle. Here, inspired by the Chinese-acupuncture therapy that employs microneedles to dredge the cell microenvironment, a microneedle-array templated extrusion (MATE) technology is proposed along with an AMME-therapy theory to address the above challenges. Specifically, a unique clay-alike thixotropic (CAT) slurry through sol-binder is first fabricated with significant capabilities in 3D-morphing. Enabled by this morphable CAT-slurry, MATE technology is further developed to rapidly and seamlessly fabricate high-throughput 3D thick electrodes with customizable ordered ion-transport channels. Consequently, the optimized 3D thick electrode shows a remarkable improvement in specific capacity by 300% even at an ultrahigh active-material loading of 60 mg cm^-2 (ca. 3 times the commercial level). Finally, an AMME therapy theory based on an artificial potential field algorithm for ion-transport path optimization is established to understand the enhanced ion-transport dynamics. The proposed AMME-therapy theory and industry-friendly MATE technology could advance the design and fabrication of high-throughput electrodes in batteries and other electrochemical energy-storage devices.