The fast-changing nature of sustainable mobility and the exponential growth of electric vehicles (EVs) have now placed battery supply chains (SCs) at the forefront of environmental concern. This review article examines 84 peer-reviewed studies published between 2008 and 2025, highlighting that 78% of the studies were published from 2020 to 2025, reflecting the rapid acceleration of EV battery sustainability research in recent years. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses method, the review has identified significant environmental hotspots and trade-off issues across six phases of the battery SC, as well as inconsistencies regarding methodology, such as functional units of measurement, and missing data in relation to the Global South. Hotspots are most prominent in South America and Central Africa (extraction), China and South Korea (manufacturing) and Southeast Asia (end-of-life). New contributions include a comparison of the life cycle assessment approaches, using new data from 2023 to 2025, adding updated insights on policy evolution, improved recycling efficiencies and digital traceability technologies that enhance supply-chain transparency. Furthermore, this review highlights ignored areas, such as informal recycling of batteries and unfair regulations across borders, and it provides recommendations, which are relevant to policymakers, industry and academia, to improve transparency in the SC, better compliance with environmental, social and governance requirements and sustainability initiatives.