Manufacturing scalability implications of materials choice in inorganic solid-state batteries

Abstract

The pursuit of scalable and manufacturable all-solid-state batteries continues to intensify, motivated by the rapidly increasing demand for safe, dense electrical energy storage. In this Perspective, we describe the numerous, often conflicting, implications of materials choices that have been made in the search for effective mitigations to the interfacial instabilities plaguing solid-state batteries. Specifically, we show that the manufacturing scalability of solid-state batteries can be governed by at least three principal consequences of materials selection: (1) the availability, scaling capacity, and price volatility of the chosen materials' constituents, (2) the manufacturing processes needed to integrate the chosen materials into full cells, and (3) the cell performance that may be practically achieved with the chosen materials and processes. While each of these factors is, in isolation, a pivotal determinant of manufacturing scalability, we show that consideration and optimization of their collective effects and tradeoffs is necessary to more completely chart a scalable pathway to manufacturing. Context & Scale With examples pulled from recent developments in solid-state batteries, we illustrate the consequences of materials choice on materials availability, processing requirements and challenges, and resultant device performance. We demonstrate that while each of these factors is, by itself, essential to understanding manufacturing scalability, joint consideration of all three provides for a more comprehensive understanding of the specific factors that could impede the scale up to production. Much of the recent activity in solidstate battery research has been aimed at mitigating the various interfacial instabilities that currently prevent the fabrication of a low cost, high performance device. With such a wide breadth of options, it can be difficult for researchers to identify the most promising or scalable pathways forward. As such, we aim to empower researchers to make more informed decisions by providing them with insights into how their materials choices are likely to impact the manufacturing scalability of different interfacial mitigation alternatives. In doing so, we hope that generalizable lessons about scalability can be extracted and applied to subsequent challenges in solid-state battery development, thereby accelerating their scale up to manufacturing.

Solid‐State Post Li Metal Ion Batteries: A Sustainable Forthcoming Reality?

“…Other factors that have been identified as pivotal for the manufacturing scalability of inorganic solid‐state cells are: i) the materials availability and price, ii) the required manufacturing processes due to materials selected, and iii) the expected performances of those materials. [ 34 ] The higher the cell energy density, the lower the production cost for each kWh, identifying the cell design as a crucial trade‐off. The examined examples of solid‐state cells including common solid electrolytes such as Li 7 La 3 Zr 2 O 12 (LLZO), Li 10 GeP 2 S 12 (LGPS), and Li 6 PS 5 Cl, and the analyses carried out on cost and performances have highlighted that the scaling of low‐cost, high performance cells can fail if the materials supply chain is strongly constrained.…”

“…Moreover, in the hypothesis that materials are readily available, the scaling might fail if those materials require costly and cumbersome manufacturing procedures during cell integration. [ 34 ] Large‐scale production of polymer‐based cells has been proven similar to conventional LIBs [ 20 ] therefore mostly compatible in terms of cell production infrastructure. On the other hand, the industrialization of solid‐state batteries containing sulfides or moisture sensitive oxides as electrolytes may present technical challenges requiring new manufacturing machinery.…”

Heavily Tungsten‐Doped Sodium Thioantimonate Solid‐State Electrolytes with Exceptionally Low Activation Energy for Ionic Diffusion

“…Although the presence of Na‐vacancies may provide a significant “add‐on” to the enhancement of ionic conductivity, its implication on the activation energy is not straightforward. This is evidenced by the measured activation energies, 0.21 and 0.18 eV, of the cubic Na 2.88 W 0.12 Sb 0.88 S 4 and Na 2.9 W 0.1 Sb 0.9 S 4 , respectively, [6, 7] which are much larger than that (≤0.08 eV) of the cubic phase of Na 3 SbS 4 [53, 67] . The activation energy, corresponding to the energy barrier of individual diffusion steps, should be largely determined by the local Na‐Na and Na‐S interactions in the system.…”

“…Here, we tune the structure and the resultant ionic conductivity/activation energy of W‐doped Na 3 SbS 4 by greatly extending the W content, going far beyond the 10–12 % reported in the previous studies [6, 7] . A heavily W‐doped system Na 2.7 W 0.3 Sb 0.7 S 4 , is successfully synthesized, and is demonstrated to display an orthorhombic structure.…”

“…Employing solid‐state electrolytes (SSEs) rather than liquid organic electrolytes is a possible path towards greater battery safety since most inorganic SSEs are non‐flammable [1–19] . Recently, there has been significant progress related to a number of successful solid‐state battery chemistries showing reasonable cycle‐life and capacity retention using traditional cathodes of Li‐ion battery (LIB) and metal anodes [20, 21] .…”