Ceramic–Salt Composite Electrolytes from Cold Sintering

Abstract

The development of solid electrolytes with the combination of high ionic conductivity, electrochemical stability, and resistance to Li dendrites continues to be a challenge. A promising approach is to create inorganic-organic composites, where multiple components provide the needed properties, but the high sintering temperature of materials such as ceramics precludes close integration or co-sintering. Here, new ceramic-salt composite electrolytes that are cold sintered at 130 °C are demonstrated. As a model system, composites of Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 (LAGP) or Li 1+x+y Al x Ti 2−x Si y P 3−y O 12 (LATP) with bis(trifluoromethanesulfonyl)imide (LiTFSI) salts are cold sintered. The resulting LAGP-LiTFSI and LATP-LiTFSI composites exhibit high relative densities of about 90% and ionic conductivities in excess of 10 −4 S cm −1 at 20 °C, which are comparable with the values obtained from LAGP and LATP sintered above 800 °C. It is also demonstrated that cold sintered LAGP-LiTFSI is electrochemically stable in Li symmetric cells over 1800 h at 0.2 mAh cm −2 . Cold sintering provides a new approach for bridging the gap in processing temperatures of different materials, thereby enabling high-performance composites for electrochemical systems.

Thermosetting polymers in cold sintering: The fabrication of ZnO‐polydimethylsiloxane composites

“…5 Al 0.5 Ge 1.5 (PO 4 ) 3 -(-CH 2 CF 2 -) x [-CF 2 CF(CF 3 )-] y , 16 Li 1. 5 Al 0.5 Ge 1.5 (PO 4 ) 3 (LAGP) or Li 1+x+y Al x Ti 2−x Si y P 3y O 12 (LATP) with bis(trifluoromethanesulfonyl)imide (LiTFSI) salts showing similar room temperature conductivity (10 −4 S·cm −1 ) as conventionally sintered ceramics, 17 Li-ion cathode LiFePO 4 -Polyvinylidene fluoride with enhanced electrochemical performances, 18 semiconductor V 2 O 5 -poly(3,4-ethylenedioxythiophene) polystyrene sulfonate composites with engineered mechanical, thermal, and electronic properties. 19 These studies highlight the new opportunities for high ceramic volume fraction (v/v >95%) ceramic-thermoplastic polymer composites enabled by cold sintering.…”

Understanding the Reactivity of a Thin Li1.5Al0.5Ge1.5(PO4)3 Solid‐State Electrolyte toward Metallic Lithium Anode

“…It is widely accepted that the use of an optimal SSE can significantly increase energy density and improve safety performance owing to its wide electrochemical window and non‐flammability. Several solid electrolytes based on polymer, [ 4 ] ceramic oxides, [ 5 ] ceramic sulfides, [ 6 ] and hybrid polymer‐ceramic [ 7 ] materials have been reported and applied in ASSLB studies. Among them, NASICON‐structured phosphate‐based electrolytes, Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 (LAGP) [ 8,9 ] and Li 1.5 Al 0.5 Ti 1.5 (PO 4 ) 3 (LATP), [ 10 ] have attracted significant attention due to their high ionic conductivity (around 10 −4 S cm −1 ), high voltage stability (up to 5 V), and excellent moisture stability.…”

Microwave Dielectric Properties of (1-x) Li2MoO4–xMg2SiO4 Composite Ceramics Fabricated by Cold Sintering Process

“…Other than the low temperature, the key processing advantages of CSP are that it produces a near shape, that the prepared dense ceramic possesses the same diameter as the model, and that no reaction occurs between different ingredients. Randall et al reported the fabrication and electrochemical properties of ceramic-salt composite electrolytes from cold sintering (Lee et al, 2019). Reaney et al addressed cold sintered C0G mulitlayer ceramic capacitors with Ag internal electrodes (Wang et al, 2019b).…”