Advancing Cobalt-Free Lithium-Ion Batteries through Electrochemical Model Refinement and Experimental Parametrization of LNMO|Gr Cells with Gel Polymer Electrolytes

Developing new battery configurations is a time-consuming process, electrochemical models can be employed to expedite the process by predicting the performance of battery designs. An electrochemical pseudo-two-dimensional modeling framework is created for both LNMO|LiPF6 in EC/PC/sulfolane|Gr and LNMO|PVdF GPE with 1.15 M LiPF6 in EC/PC/FEC/sulfolane|Gr configurations with gelifiable electrodes, leveraging the experimental characterization of battery components for enhanced accuracy. Parametrization experiments include quasi-open circuit potential, galvanostatic intermittent titration technique, electrochemical impedance spectroscopy, microscopy and the four-point resistance method. The modeling framework is initiated at full coin cell level and subsequently extended to encompass monolayered, 200 mAh and 500 mAh multilayered pouch cells. Experimental validation, through voltage-capacity measurements, ensures the accuracy of the models. The discharge curves indicate that cells incorporating GPE show similar performance with liquid electrolytes. The impact of increasing current rates on performance is examined by scrutinizing the polarization trends during discharge and the Li-ion concentration in the electrolyte phase. Elevated C-rates induce heightened polarization, detrimentally influencing performance. Importantly, the developed model for full coin cells can be seamlessly expanded to encompass 500 mAh multilayered pouch cells without requiring additional component characterization. This versatility allows the modeling framework to be a valuable tool for evaluating the performance of battery configurations at higher levels.