An Insight into the Battery Degradation for a Proposal of a Battery Friendly Charging Technique

Li-ion batteries are widely used in electric vehicles because of their promising characteristics that meet high specific power and energy density requirements. The only setback is the capacity fading due to degradation in Li-ion batteries. The rate of capacity fade in Li-ion batteries in EVs vary based on the charging rate, changes in internal cell temperature and external ambient temperature, and user driving patterns. Since the Li-ion battery is electrochemical, determining the actual cause of degradation at a particular instant and constraining the rate is a big challenge. Further, the causes are related to parameters which are chemical, electrical and mechanical. In this work, the causes of degradation are studied by analysing the variation of parameters for multiple charge types and rates at different ambient temperatures. The analysis leads to developing a new universal charging scheme suitable to fast charge battery at different ambient temperatures appropriately and constrain battery degradation.