In this study we quantify the cradle-to-gate environmental impacts of battery-grade cathode material salts manufactured in conventional and circular supply chains across three major steps: material extraction, transport, and refinement (Fig. ). First, we quantify and compare the refinement of mined concentrate from natural deposits into battery-grade materials in conventional supply chains with production of these materials by Redwood Materials (a recycling company in Nevada, U.S.). Two LIB feedstocks are explored: non-energized LIB production scrap from manufacturing facilities and energized end-of-life LIBs collected from consumers. Industrial-scale operational data provided by Redwood Materials are analyzed and compared to conventional LIB supply chain values based on Argonne National Laboratory's Greenhouse Gases, Regulated Emissions, and Energy use in Technologies (GREET 2021) model . Second, influences of the product formats in the refinement pathways on environmental impacts are examined. For both conventional and circular refinement, impacts of producing mixed Ni-Co compounds and discrete salts are analyzed. Third, we assess the environmental impacts of upstream processes before gateto-gate refinement based on modeling. The upstream assessment includes the extraction of LIB material from conventional (i.e., mined ore) or circular (i.e., collected batteries) sources and the transport of extracted material to relevant refinement facilities for production of battery-grade cathode materials as Li, Co and Ni sulfate or carbonate salts. To the best of our knowledge, this study is the first life cycle assessment with primary industrial-scale circular refinement data that includes stepwise, cradle-to-gate comparison of conventional and circular LIB supply chains. With the methodologies and results reported herein, researchers can prioritize major opportunities to improve process efficiencies, practitioners can benchmark their environmental impacts, and policymakers can incentivize best environmental practices in LIB supply chain management.