Aging-Aware optimal charging strategy for lithium-ion batteries: Considering aging status and electro-thermal-aging dynamics

Abstract

High quality charging strategy, which can minimize the impact of inevitable aging/degradation mechanisms and avoid unfavorable side reactions, is critical for battery management systems to extend the battery life, maximize charging capability, ensure safety, and improve the overall system reliability. An aging-aware optimal charging strategy is proposed in this effort to avoid the formation of lithium plating and minimize the charging time and/or capacity loss due to solid electrolyte interface (SEI) layer growth and active material loss. A physics-based reduced-order lithium plating model is developed based on the solid and electrolyte phase charge conservation equations, and used in the optimal charging strategy to prevent the occurrence of lithium deposition. The interaction between SEI layer growth, reduction of anode porosity, and lithium plating is also investigated. The proposed charging strategy provides the flexibility to be further calibrated into three strategies: aging-aware minimum-time strategy, aging-aware minimum-capacity-loss strategy, and minimum time and capacity loss balanced strategy. They are compared against each other and evaluated with a fresh battery, a moderately aged battery, and a fully aged battery, to demonstrate how the aging status of the battery impacts the charging strategies.