Outlook on K-Ion Batteries

Due to the rapid battery market expansion, and the limited and geographically concentrated lithium and cobalt resources, there is significant concern regarding the short-term supply and long-term sustainability of lithium-ion batteries (LIBs). Potassium-ion batteries (KIBs) are emerging as a promising complementary technology to LIBs due to the relative abundance of potassium. KIBs can also use graphite anodes providing a critical advantage over sodium-ion batteries (NIBs). In this perspective, we provide an overview of the most promising cathodes, anodes, and electrolytes to date for KIBs. We also present a concise techno-economic model to critically compare the most promising KIB chemistries and evaluate if they can compete with a leading NIB and LIBs. Finally, we identify five critical research challenges that need to be addressed for KIBs to become a viable technology.