Li 2 CO 3 particles impacts the synthetic pathway by limiting the contact area between the TM (oxy)hydroxide precursor and the Li source. As the particle size of Li 2 CO 3 increases, its specific surface area decreases, to the point that some TM (oxy)hydroxide precursor particles are not in direct solid-solid contact with the Li source. During calcination, TM (oxy)hydroxide particles in direct contact with a Li source will lithiate via the solid-solid pathway -i.e., all TM (oxy)hydroxide particles in the SL-LMR case, and whatever subset of TM (oxy)hydroxide particles is in contact with the Li source in the AR-LMR case. On the other hand, "orphaned" TM (oxy)hydroxide precursor particles do not fully lithiate until the Li 2 CO 3 melt permeates the reaction vessel, and so follow the solid-liquid lithiation pathway.