Next Generation Battery Materials

Description: synthesis approachLithium ion batteries (LIBs) currently dominate the market and are expected to for another decade as costs decline. However, with performance approaching intrinsic material limits, LIBs cannot meet the increasing demands of electric vehicles, advanced consumer electronics, and stationary storage. In the next decade both solid state and lithium-sulfur (Li-S) batteries are expected to start displacing LIBs, and the market for these alternatives is forecast to be over $30 billion by 2035. Central to both technologies is Li2S, which serves as the active cathode material in Li-S batteries and is the key precursor and cost driver for leading solid-state electrolytes. In both applications Li2S has demonstrated excellent performance when used in nanoparticle form. However, Li2S is very costly and commercially available only as micropowders with impurities being a major concern, reflecting the energy-intensive carbothermal reduction processes currently used for synthesis. The sodium analogue (Na2S) is also of interest for low cost, stationary storage applications.

Description: synthesis approach We recently invented a green chemistry-inspired approach for synthesizing alkali sulfide (M2S, M = Li and Na) nanocrystals through the reaction of hydrogen sulfide (H2S) gas with alkali metal-organic (M-R) complexes in solution as shown schematically at left. This thermodynamically favorable reaction occurs spontaneously and proceeds rapidly to completion with near 100% atom efficiency at ambient temperature, forming phase-pure, anhydrous M2S nanocrystals (NCs) that may be readily recovered from solution. H2S, a major industrial waste, is completely abated and the valuable hydrogen stored therein may be fully recovered as H2. As such, this innovative synthetic approach is expected to be scalable, energy-efficient, and cost-effective. A great advantage of this solution based approach is that the size and shape of the NCs may be tuned through judicious selection of parameters such as solvent, concnetration, and the organic complexing agent. In addition to understanding the basic chemistry we are developing bubble columns as a scalable manufacturing platform for prodcuing these nanomaterials. Process-structure-property perfromance relationships are being developed for the application of these materials by fabricating and testing advanced cathodes and solid state electrolytes. In the case of the former we have approached theoretical capacity (1164 mAh/g) and have observed great benefits in making glassy precursors for solid state electolytes.This project is lead by PhD candidates Will Smith and Saeed Ahmadi Vaselabadi who are leading scaleup of Li2S synthesis and solution based fabrication of solid state electrolytes. MS candidtae Courtney Clark is examining the technoeconomics and undergraduate Jerry Birnbaum keeps everyone honest.  

Description: synthesis approach

Description: synthesis approach This project is supported by the National Science Foundation through award 1825470. In additon we acknowledge an Advanced Industries Accelerator grant from the the Colorado Office of Economic Development and Intenational Trade (COEDIT) with support from our industrial partner SolidPower. Lastly we acknowledge support for JB provided through a Mines Undergraduate Research Fellowship (MURF).