Investigating Li-ion batteries negative electrode swelling processes using electrochemical dilatometer

Abstract

International audienceLi-ion batteries despite being the most commercialised electrochemical energy storage system are still suffering some drawbacks during their cycling. Indeed, several processes are taking place during cycling, i) the electrodes are “breathing” during oxidation and reduction, ii) the electrolyte is reduced and oxidised generating several surface reactions among them the well-known solid electrolyte interphase (SEI). As an example, at the negative electrode, graphite is suffering a volume expansion of up to 10% that is generally reversible but upon long-term cycling can be a caused of fading (ref.1). This induced mechanical stress and its consequence on the electrochemical performance need to be investigated