Development of Next Generation Solid-State Batteries and the Path to Manufacturing

A critical difference between conventional rechargeable batteries and solid-state batteries is the substitution of a solid electrolyte for the volatile (and typically flammable) liquid electrolyte. However, this substitution is non-trivial and has significant implications for the structure, performance, manufacture, and cost of solid-state batteries. The scaling and manufacture of polymer electrolytes is relatively straightforward but their low ionic conductivity at room temperature precludes widespread adoption. A number of polycrystalline solid electrolytes have excellent room temperature ionic conductivities, however the difficulty in maintaining solid-solid contacts in composite electrodes is challenging, and the scaling of polycrystalline ceramic sheet is also nontrivial and likely expensive. Oxide glasses have been used successfully in commercial solid-state micro-batteries, but these batteries are made by physical vapor deposition and therefore very expensive to produce. Sulfide glass solid electrolytes have the advantages of being relatively soft and therefore easier to establish solid-solid contacts, and can be scaled using conventional thin glass processing technology. However, sulfide electrolytes are sensitive to moisture which introduces its own complexity in manufacturing. In this presentation we will examine the merits and challenges of each approach and potential paths to commercialization of high energy density solid-state batteries.