(Invited) Processability of Solid-State Batteries

Abstract

Solid-state batteries are promising energy storage alternatives that can achieve high energy densities be enabling Li metal anode and high voltage cathodes. When combined with long cycle life, improved safety, and low cost (<$100/kWh) the value proposition of solid-state lithium metal battery becomes more and more relevant. There are, however, significant materials and processing challenges that disrupt the materialization of working SSBs at present. Recent reviews clearly informed that the energy and power densities of the reported SSBs fall short in comparison with the state-of-the-art Li-ion batteries. The technical barriers to be addressed in the long-term include achieving areal capacities in the range of 3-10 mAh cm-2 with less than 10% excess Li anode, and more than 70% active that material loading in solid-state composite cathodes that are assembled against thin electrolytes which can withstand current densities higher than 1 mA cm-2, and yet enables higher coulombic efficiencies. Cell design calculations show that solid electrolytes with <100 µm thicknesses and Li metal anode with <50 µm thickness are necessary to achieve energy densities comparable or higher than the state-of-the-art lithium-ion batteries. The processability and integration of thick composite cathodes, thin solid electrolytes, and thin lithium metal anode into cell configurations in scalable fashions are of utmost significance to improve the value proposition of near market SSBs.