Levelized Cost of Storage Framework for Solid-State Batteries in 400V/800V Electric Vehicle Powertrains

Electric Vehicle (EV) manufacturers are adopting a range of powertrain architectures, with voltage systems ranging from 400V to 800V. The voltage ranges improves the efficiency and performance of EV powertrains. This improvement transforms EVs into more than just transportation systems. They also integrate the EVs as critical distributed energy storage units, and helps in grid stability, and energy load balancing through vehicle-to-grid (V2G) integration. Solid-state batteries (SSBs) represent an advanced energy storage technology, which enable EVs to operate efficiently at higher voltage configurations. To evaluate their feasibility and cost-effectiveness, the Levelized Cost of Storage (LCOS) serves as a critical metric. A low LCOS indicates improved cost-efficiency, and is achieved through careful optimization of capital expenditure (CapEx), reduced operational expenditure (OpEx), and minimized energy losses, during operation. In contrast, a high LCOS, exposes inefficiencies in system integration, lifecycle design, or operational management. This paper develops a detailed LCOS framework, for the deployment of SSBs in 400V and 800V EV powertrain topologies. The model uses mathematical formulations across various automotive platforms. Simulation results show that 800V EVs have a lower LCOS, compared to 400V systems. These findings support the economic and technical viability of SSBs in high-voltage EV powertrains. Key words. Electric Vehicle, Solid State Battery, Levelized Cost of Storage