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Hi All..

I am working on the charging-discharging of a 2D lithium ion battery. My electrode is a 2D multiple particle electrode consisting of three multi-sized particles. I am studing the temporal evolution of surface state of charge (SOC) of all particles during lithiation.

I consided all the particles at initial solid concentration and applied the Bulter Volmer current density on the surface of all particles.

When I solved the model, my results showed that during lithiation, the surface SOC of small particle increased faster than the large particle even all the particles are at the same distance from separator.

1. My question is why the surface SOC of small particle increased faster than the large particle. In my case the small particles reached 100% SOC at 1000 seconds of lithiation and the large particle achieved 56% SOC.

2. The surface SOC of large particle increased to 56% at 400 seconds of lithiation and then decreased to 55% at the end of lithiation( i.e. 1000 seconds)

I will be really thankful if someone expalin me the basic mechanism behined this phenomenon. Thanks