Design optimization of LiNi0.6Co0.2Mn0.2O2/graphite lithium-ion cells based on simulation and experimental data

• Published in: Journal of power sources Vol. 319; pp. 147 - 158
• Main Authors: Appiah, Williams Agyei, Park, Joonam, Song, Seonghyun, Byun, Seoungwoo, Ryou, Myung-Hyun, Lee, Yong Min
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2016
• Subjects: Electrode thickness and porosity; Lithium ion cell; Ragone plot; Simulation; Specific energy and power; Lithium ion cell; Specific energy and power; Simulation; Ragone plot; Electrode thickness and porosity
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2016.04.052

LiNi0.6Co0.2Mn0.2O2 cathodes of different thicknesses and porosities are prepared and tested, in order to optimize the design of lithium-ion cells. A mathematical model for simulating multiple types of particles with different contact resistances in a single electrode is adopted to study the effects of the different cathode thicknesses and porosities on lithium-ion transport using the nonlinear least squares technique. The model is used to optimize the design of LiNi0.6Co0.2Mn0.2O2/graphite lithium-ion cells by employing it to generate a number of Ragone plots. The cells are optimized for cathode porosity and thickness, while the anode porosity, anode-to-cathode capacity ratio, thickness and porosity of separator, and electrolyte salt concentration are held constant. Optimization is performed for discharge times ranging from 10 h to 5 min. Using the Levenberg-Marquardt method as a fitting technique, accounting for multiple particles with different contact resistances, and employing a rate-dependent solid-phase diffusion coefficient results in there being good agreement between the simulated and experimentally determined discharge curves. The optimized parameters obtained from this study should serve as a guide for the battery industry as well as for researchers for determining the optimal cell design for different applications. •Simulation and well-designed experiments on LiNi0.6Co0.2Mn0.2O2/graphite cell.•Correlation between Li-ion transport and cathode designs are demonstrated.•A relation between electrochemical performance and cathode designs are exhibited.•Optimization of cathode designs for higher specific energy/power using Ragone plot.