Conclusions

A review was undertaken on the use of chemical stabilisation techniques that have been used in literature to pre-treat LIBs before they are recycled. The review of literature focused specifically on chemical stabilisation of the cells as a means to make the storage, transportation and processing of LIBs safer. It was found that a significant number of authors make use of chemical stabilisation techniques without fully understanding the risks associated with them. Most did not consider the impacts the stabilisation technique has on the downstream recycling processes and looked solely at what was the cheapest and fastest way to stop a cell from producing an electrical charge. Only a few studies highlighted the risks and problems associated with chemical stabilisation techniques. These include risks of corrosion and leakage of the electrolyte solution into the discharging solution, the generation of hazardous gases through the discharging process, and voltage rebound after removal from the discharge solution. Unfortunately, as these risks are, for the most part, not recognised by the users of the technique, it is likely that in many cases there is severe environmental impact that is overlooked. In the case of voltage rebound, users of chemical stabilisation techniques may be falsely led to believe that the batteries are discharged after submersion in a salt solution, and therefore that the batteries can be safely stored without the risk of fire or explosion. One way to avoid negative impacts of voltage rebound is shorting of the terminals immediately after stabilisation. An interesting observation from this study was that, although most literature focuses on the use of chemical stabilisation techniques, only a small portion of industrial processes use these techniques. Many industrial processes use in-situ chemical stabilisation techniques as they shred the batteries under either a salt solution (or water) to prevent fires and explosions.