Multi-objective optimization of a lithium cell design operating in a cyclic process

AIMO, CORINA; SCHMIDHALTER, IGNACIO; AGUIRRE, PIO

Journal of Energy Storage

ELSEVIER

Lugar: AMSTERDAM; Año: 2023 vol. 57

2352-152X

Multi-objective optimization frameworks of lithium-ion whole-cell design operating in a cyclic process arepresented in this paper. The objective functions involved are maximization of capacity, maximization of specificenergy in discharge and maximization of cycle energy efficiency. The considered design variables are electrodethicknesses, solid volume fraction and porosity of electrode compartments, and cell mass per unit cross-sectionalarea. In addition, the constant current value of charge and discharge is optimized. A phenomenological mathematical model developed in GAMS (General Algebraic Modeling System) environment is applied to achieve thestated goals and the multi-objective problems are solved using an epsilon constraint method-based, which iseffective for finding solutions in non-convex feasible regions. Solutions for two different cell chemistries areanalyzed: LMO and LCO. Pareto curves and surfaces are obtained and sets of solutions with the highest contradictions and with the most balanced agreement between the objectives involved are identified. Whencomparing optimal LMO designs with optimal LCO designs, the former result on average 48 % less capacity, 19 %less specific energy and 31 % more energy efficiency. Results show that material type-dependent variables suchas active solids have a strong influence on the specific energy and cycle energy efficiency. While the electrodethicknesses show a general trend regardless of the type of chemistry, presenting a strong influence on cell capacity values.