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.