On safety of lithium-ion cells

Safety of lithium-ion cells is mainly related to thermal reactivity of the components. Active materials play a major role: carbon materials because they directly influence the kinetics of reactions at the negative electrode, positive materials because of their relation with their respective delithiation state. Adequately substituted nickel based materials appear as the most stable positive materials. Electrolyte is mainly concerned through its reactivity with lithium of LixC6 and with O2 generated by the positive materials decomposition. Moreover, non-active materials, in particular binders, also clearly influence thermal stability and consequently safety behaviour of lithium-ion cells.