Cold sintering-enabled interface engineering of composites for solid-state batteries

Abstract

The cold sintering process (CSP) is a low-temperature consolidation method used to fabricate materials and their composites by applying transient solvents and external pressure. In this mechano-chemical process, the local dissolution, solvent evaporation, and supersaturation of the solute lead to “solution-precipitation” for consolidating various materials to nearly full densification, mimicking the natural pressure solution creep. Because of the low processing temperature (<300°C), it can bridge the temperature gap between ceramics, metals, and polymers for co-sintering composites. Therefore, CSP provides a promising strategy of interface engineering to readily integrate high-processing temperature ceramic materials (e.g., active electrode materials, ceramic solid-state electrolytes) as “grains” and low-melting-point additives (e.g., polymer binders, lithium salts, or solid-state polymer electrolytes) as “grain boundaries.” In this minireview, the mechanisms of geomimetics CSP and energy dissipations are discussed and compared to other sintering technologies. Specifically, the sintering dynamics and various sintering aids/conditions methods are reviewed to assist the low energy consumption processes. We also discuss the CSP-enabled consolidation and interface engineering for composite electrodes, composite solid-state electrolytes, and multi-component laminated structure battery devices for high-performance solid-state batteries. We then conclude the present review with a perspective on future opportunities and challenges.

Spray-Printed Flexible Li2S Cathode with Inorganic Ion-Conductive Binder Nano-Li3PS4

“…This quasi-liquid phase promotes the diffusion between Li 3 PS 4 nanoparticles, thereby sintering to obtain a dense film. This mechanism has been widely observed for an emerging sintering technique called cold sintering process. , …”

“…This mechanism has been widely observed for an emerging sintering technique called cold sintering process. 31,32 Benefiting from the low-temperature sintering of the solvated Li 3 PS 4 nanoparticles, they can be used as ionconductive inorganic binder for the composite cathode of ASSBs. To visualize how these nanoparticles bind the cathode components together, two Li 2 S cathode inks, with and without the solvated Li 3 PS 4 nanoparticles, are spray-printed onto Al foil, sintered at 250 °C, and their morphology are recorded by SEM.…”

Multifunctional composite designs for structural energy storage

“…This research encompasses the development of novel manufacturing processes to seamlessly integrate batteries into building structures without compromising their performance and durability. Thereby, efforts are directed towards enhancing multicomponent compatibility, manufacturing efficiency, and cost‐effectiveness, aiming to make structural batteries more accessible and affordable 34,35 . For instance, a 3D printing technique co‐extruded continuous CFs and doped functional photopolymer resin, cured by a UV laser, enabling the fabrication of multifunctional composite materials.…”

“…Thereby, efforts are directed towards enhancing multicomponent compatibility, manufacturing efficiency, and cost-effectiveness, aiming to make structural batteries more accessible and affordable. 34,35 For instance, a 3D printing technique co-extruded continuous CFs and doped functional photopolymer resin, cured by a UV laser, enabling the fabrication of multifunctional composite materials. Notably, this approach enables the printing of a functional lithium-ion structural battery in a single step (Figure 1D).…”