Batteries are the elements that sustain our use of devices such as smartphones and computers. In this sense, in recent years work has been done on tasks such as increasing its capacity, life time and loading speed. In this way, we have fast charging as a great feature although it can generate problems in the equipment. In that sense, a study has found one of the reasons that causes lithium ion batteries to degrade with fast charging.
This is an effect that has been called “Plating” that prevents the lithium ion particles from being inserted correctly into the graphite of the batteries.
Fast charging and degradation of lithium ion batteries
To understand this topic developed by researchers at the Argonne National Laboratory of the United States Department of Energy, we must be clear about how the battery works. In that sense, to make it simple we have that the batteries have the so-called cathodes and anodes, the first positively charged and the second negatively charged. These elements are separated by a material made of graphite and called electrolyte that is responsible for moving the lithium ion particles between the cathode and the anode.
This graphite material is created from small particles and it is within them where the lithium ion particles are inserted to produce the charging and discharging processes. The latter is called “Interleaving” and is the secret behind charging any battery.
The problem lies in the fact that fast charging in lithium ion batteries complicates the interleaving process. In this way, instead of the lithium ion being inserted into the graphite particles, it ends up accumulating at the anode and forming a layer. Basically, what happens is a deformation of the graphite particle network that prevents the lithium ion from reaching successfully. Hence, this immediately causes battery damage.
Daniel Abraham, director of this study, says that the solution lies in finding more efficient ways for the lithium ion to reach graphite. Another alternative is to make the graphite lattices stronger so that fast charging does not easily mess them up. In this way, it becomes much clearer why fast charging in lithium ion batteries tends to degrade them.
