Enabling Innovation in Solid-State Battery Development

A Case Study of "Incorporating Solvate and Solid Electrolytes for All-Solid-state Li₂S Batteries with High Capacity and Long Cycle Life"

Introduction

Solid-state lithium-sulfur batteries have recently achieved a groundbreaking breakthrough in their experimental development that overcomes previous performance limitations.  Academic researchers Minjeong Shin and Andrew A. Gewirth from the University of Illinois’s Department of Chemistry first communicated this discovery through their paper "Incorporating Solvate and Solid Electrolytes for All-Solid-state Li₂S Batteries with High Capacity and Long Cycle Life", published in Advanced Energy Materials on May 2019.  In the paper, the team discussed how they developed a new materials that would increase the performance of these batteries, thereby making them a commercially viable replacement for current liquid electrolyte batteries.  In order to acquire the high-quality materials and machinery they needed to complete their research project, the team sourced key components for their experiments from MSE Supplies.  Through this collaboration between academia and industry, the team successfully completed their research project with stellar results that have shown great promise for the future of the solid-state battery technology landscape.

The Research

Development of solid-state lithium-sulfur batteries had been stalled due to the poor interface between the solid electrolyte and the battery electrodes.  Solid materials are generally unable to conform to the surface of the electrodes as closely as liquid electrolytes, leading to poor interfacial interactions and an overall reduction of battery performance.  This low performance manifests itself in two primary ways:

• Low ionic and electronic conductivity in the battery due to the active materials’ inability to interact with optimal efficiency.

• Low cyclability of the battery due to the large volume changes in the solid electrolyte causing cracks to form in the electrodes’ structure.

Modification of the interface between the solid-state electrolyte and the electrode layers in the battery is thus necessary in order to overcome these drawbacks.  Shin and Gewirth decided to solve this problem with two potential fixes: introducing a solvate interlayer between the electrolyte and electrodes and mixing in the solvate directly with the electrolyte to enhance its interfacial performance. 

Figure 1: Schematic representation of the interaction of the battery materials a) without and b) with the solvate interlayer.  Source University of Illinois.

Experimental results demonstrated that the solvate interlayer in the solid-state battery cells successfully lowered the cell impedance and improved the cyclability of the battery beyond those of the cells without the interlayer.  In addition, the performance of the battery was enhanced even further when the solvate was directly mixed into the solid-state electrolyte to create a hybrid “solvSEM” material.  Both solutions were able to effectively increase the interfacial interaction between the solid-state electrolyte and the electrodes due to the enhanced malleability and electrochemical performance of the new materials.

The Products

MSE Supplies provided materials and machines from two of its major product categories in order to facilitate Shiin and Gewirth’s research and ensure they had high quality materials with which to conduct their experiments.  The composite cathode for the Li₂S battery that served as the demonstrative battery cell for the experiment was synthesized from a combination of Li₂S, Ketjenblack, and Li₇P₃S₁₁ (LPS, 99.99%) powder from MSE Supplies. MSE Supplies’ LPS powder is created by our partner company, Ampcera, with state-of-the-art production techniques that ensure the highest quality of battery powder materials.  In addition to the raw materials, MSE Supplies also provided a planetary ball mill machine in order to effectively mill the Li₂S into a useable particle size.

Figure 2: SEM image of Ampcera’s Li₇P₃S₁₁ (LPS) powder. Source: MSE Supplies.

Lithium battery materials for research and development, such as cathode, anode, and solid-state electrolyte materials, can be found at MSE Supplies.  The solid-state electrolyte materials are state-of-the-art, proprietary compounds synthesized by our partner company, Ampcera. 

Comprehensive ball milling and grinding solutions can be found at MSE Supplies.  All three major components of the ball milling system are supplied: the ball mills, the mill jars, and the milling media. 

Source

Shin, Minjeong & Gewirth, Andrew. (2019). Incorporating Solvate and Solid Electrolytes for All‐Solid‐State Li2S Batteries with High Capacity and Long Cycle Life. Advanced Energy Materials. 10.1002/aenm.201900938. https://www.researchgate.net/profile/Minjeong_Shin2/publication/
333436380_Incorporating_Solvate_and_Solid_Electrolytes_for_All-Solid-State_Li2S_Batteries_with_High_Capacity_and_Long_Cycle_Life/
links/5d56e87345851545af48df7f/Incorporating-Solvate-and-Solid-Electrolytes-for-All-Solid-State-Li2S-Batteries-with-High-Capacity-and-Long-Cycle-Life.pdf