The increasing penetration of renewable energy sources in modern power systems is essential to achieve sustainable energy transitions; however, their inherent intermittency continues to pose challenges to system reliability and operational stability. Energy storage systems are therefore indispensable, and lithium
ion batteries are emerging as a key technology because of their high efficiency, favorable energy density, and widespread deployment. As lithium-ion batteries are increasingly utilized in electric vehicles and grid integrated applications, accurate modeling of battery degradation has become critical for assessing long term performance and economic feasibility. Vehicle-to-Grid (V2G) operation, which enables bidirectional power exchange between electric vehicles and the grid, offers significant system-level benefits but introduces additional battery cycling and operating stress.

This study presents a two-year simulation framework to investigate lithium-ion battery degradation under driving and combined driving–V2G operations. A comparative analysis is conducted across multiple battery chemistries, including nickel–manganese–cobalt (NMC/Graphite), lithium iron phosphate (LFP/Graphite),lithium titanate oxide (NMC/LTO) and a hybrid configuration combining (NMC/Graphite) and (NMC/LTO) batteries. An empirical degradation model for the (NMC/LTO) battery is developed and validated using experimental data available in the literature. Degradation models for (NMC/Graphite) and (LFP/Graphite)batteries are adopted from existing studies. In addition, a hybrid degradation model combining NMC and LTO chemistries is introduced to investigate the potential advantages of hybrid battery architectures. Battery power profiles derived from the Worldwide Harmonized Light Vehicles Test Procedure (WLTP) driving cycle are used to represent both conventional driving and V2G-enabled operation. Three simulation scenarios are considered: a baseline driving scenario, a V2G operation scenario, and a sensitivity analysis scenario evaluating the influence of increasing the share of (NMC/LTO) in the hybrid configuration.

The results validate the empirical degradation model developed for the (NMC/LTO), and (NMC/Graphite, NMC/LTO),demonstratinggoodagreementwiththeobservedlong-termagingbehavior.A comparative analysis with conventional (NMC/ Graphite) and (LFP/Graphite) chemistries revealed that LTO-based and hybrid configurations exhibit enhanced degradation resistance under normal operating conditions and V2G operation.