The Electrolyte as the Battery’s Underdog: Its Role in Performance, Safety and Sustainability (and How We Can Make It Better)

After more than 30 years of improving lithium-ion batteries, sustainability is finally catching up with performance as a priority. Yet, most researchers still focus on electrode materials, while overlooking another crucial partner: the electrolyte. Despite accounting for only 12-16 wt.% of the cell, the electrolyte plays an essential role in performance, sustainability, and safety. In this regard, current commercial electrolytes are far from ideal:  carbonate-based solvents are fossil-fuel derived and highly flammable, while the commonly used LiPF6 salt comes from intensive mining and raises serious safety and environmental concerns.

To tackle these challenges, we need a full understanding of how electrolytes are made, from the precursor to the final component level. Building from this broader perspective, most recent research on electrolyte optimization will be explored, including bio-derived solvents, fluorine-free salts, and novel recycling approaches that can pave the way toward safer and more sustainable energy storage devices. Ultimately, sustainability and recyclability will be explored through the often-overlooked lens of the electrolyte.