Healing the battery and the planet: An environmental perspective on self-healing batteries for smartphones

The impact on climate change (CC) of smartphones is expected to rise, due to their short lifetime and increasing demand. The battery of a smartphone is the component with the highest failure rate, emphasizing the need for long-lasting batteries. In this regard, a self-healing (SH) battery for smartphones has been developed, with lithium nickel manganese nickel oxide (NMC) and silicon as active materials. To understand the environmental impacts, a life cycle assessment (LCA) of an SH battery is performed for the first time, with a thorough sensitivity analysis on the influence of key raw materials supply routes. Inventories for cobalt sulfate, copper, lithium hydroxide, nickel sulfate, and silicon nanoparticles production have been gathered. The end-of-life (EoL) specificities of smartphones are considered: recycling, landfill, and incineration rates are calculated based on European waste statistics. The results of the 16 impact categories of the Environmental Footprint 3.1 method show that the silicon active material is relatively important, but the use stage is the main contributor to the impact on CC. The SH polymer's low contribution (below 3% for 15 categories) is a good sign of the potential benefits of this technology. To compensate for the additional impacts of the SH polymer, the battery should deliver 12% more energy than a non-SH battery, over its lifetime. The sensitivity analysis reveals the importance of modeling raw material production in LCA of the batteries. Notably, nickel sulfate influence is remarkable and the use of database averages for this material to analyze the environmental impacts of batteries is questionable. Thus, future research should gather primary data for nickel sulfate to enhance our understanding of the full environmental potential of batteries. Finally, the results show the importance of the battery lifetime, emphasizing the relevance of SH capabilities in batteries.