Solid‑state batteries are widely regarded as a next‑generation battery technology capable of delivering improvements in safety, energy density, cycle life and charging performance relative to conventional liquid electrolyte lithium‑ion systems. While global attention has largely focused on cell design and electrochemical performance, less consideration has been given to the upstream implications for critical mineral supply chains, precursor processing, and value‑added opportunities. This paper examines the leading solid‑state battery chemistry pathways currently under development, including sulfide‑based, oxide‑based and emerging sodium‑based systems. Emphasis is placed on the mineral precursors required for each chemistry, their processing routes, and the technical challenges associated with achieving the purity, consistency, and scale demanded by advanced battery manufacture. The analysis highlights how different electrolyte chemistries generate materially different demand profiles, with lithium and phosphorus emerging as the most strategically relevant precursor elements in an Australian context, supported by additional requirements for sulfur, sodium, aluminium, silicon, lanthanum, titanium, zirconium and germanium. Particular focus is given to sulfide and oxide electrolyte systems, which currently dominate research activity and early commercialisation efforts, together with sodium‑based systems as an adjacent pathway. These systems present both opportunities and constraints from a minerals processing perspective, including moisture‑sensitive sulfide handling, high-temperature ceramic processing and the need for tightly controlled impurity management. Conversely, they also offer potential pathways for downstream processing and chemical manufacturing that extend beyond traditional concentrate production. The paper further considers where strategic opportunities may exist for Australia within the evolving solid‑state battery supply chain, particularly in the context of national critical minerals strategies and investment frameworks. By linking battery chemistry to precursor requirements and downstream processing routes, this work aims to support more informed policy, investment, and project development decisions. Solid‑state batteries are therefore framed not only as a battery technology, but as a shift in future critical mineral demand and downstream precursor production. This perspective provides timely context for stakeholders seeking resilient, diversified, and technically informed pathways into emerging battery materials markets globally.