Analysis of the benefits of increasing the battery voltage of electric vehicles to 800 V

Abstract

The presented study analyzes the strategic transition of the automotive industry from traditional 400-volt traction battery systems to advanced high-voltage architectures of 800 V and above. The relevance of the work is due to the global challenges of decarbonization of the transport sector and the need to reduce charging times. The author examines in detail the physical limits of existing systems, where the main barrier is significant resistive losses (I2R), which lead to excess heat generation and require the use of massive cable systems. It is established that the 400 V architecture, despite its economic feasibility and developed base of compatible infrastructure, has exhausted the potential for the implementation of ultra-fast charging protocols, which makes the transition to an increased operating voltage a technically unalternative stage in the evolution of modern electric transport.

The work places special emphasis on the technological transformation of the component base, in particular, on the transition from silicon semiconductors (Si IGBT) to wide-gap components based on silicon carbide (SiC). It is investigated how doubling the voltage allows to reduce the current strength by half while maintaining identical power, which not only minimizes the thermal load on the battery cells, but also allows to reduce the mass of conductive materials by 20–30%. Special attention is paid to innovative thermal management methods, including integrated liquid and immersion cooling systems, which ensure the stability of electrochemical processes and significantly slow down the degradation of battery capacity under conditions of ultra-high loads.

The final part of the study is devoted to the analysis of the compatibility of high-voltage vehicles with the existing infrastructure and the forecasting of the further development of the industry towards 1200 V systems. It is substantiated that the integration of 800 V systems into the mass segment of electric vehicles, despite the higher initial cost of SiC components, provides a significant increase in overall energy efficiency and competitiveness. The conclusions of the work indicate that future projects, such as the European ENLIGHTEN initiative, create the foundation for the final replacement of ICE cars by achieving parity in refueling speed and energy autonomy.