Despite the intention of the battery industry to provide an environmentally friendly solution to the energy transition and decarbonisation, the present and future scale of battery production raises concerns about the potential for pollution, particularly as commercial battery chemistries contain at least 4.53 wt% of anthropogenic fluorine, including per- and poly-fluoroalkyl substances (PFAS). In this review, we explain the reasons for concern regarding fluorine compounds and outline the ways in which fluorines could be released to the environment across the lithium-ion battery supply chain, from mining of the raw materials required for battery production, to emissions from battery fires and end-of-life processing or disposal. We estimate the scale of fluorine contained within batteries produced this year to be 0.235 Mt F, rising to 1 Mt F in 2035. Considering that recycling methods do not yet target electrolyte or binder recovery, all of this could potentially be released to the environment in the next few decades. We highlight the need for alternatives to be sought and review some of the alternatives that have been proposed for batteries, summarising the relevant global regulations and their impact. However, we are conscious that the battery industry is under far more scrutiny than incumbent industries and we therefore include a section which sets the battery industry in context against other industries, including oil and gas, which also emit fluorine compounds, including PFAS.