Technological Development Trajectories of the Component Technologies in Battery Electric Vehicles

Abstract

As the concern about climate change grows, interest in battery electric vehicles (BEVs) is rising. BEVs are forecasted to constitute about 40% of passenger vehicle sales in 2035. While BEVs produce no emissions from the tailpipe, they face challenges, such as driving range and refueling time, that require technological advancements to improve performance and social acceptance. Since the evolution and replacement of component technologies have propelled the BEV progress, mapping their development trajectories may yield insights into future evolutions.

This thesis explores the technological development trajectories of batteries, ultra capacitors, battery management systems, electric motors, power electronics, and heat pumps, using main path analysis with U.S. patents published up to 2023. This analysis method can detect technological development trajectories and key patents in the trajectories by identifying the patents frequently cited, taking advantage of enormous patent data.

The results reveal that critical innovations do not necessarily occur when many innovations occur. Regarding some technological categories in some technology fields, such as battery circuit arrangements of power electronics, important innovations have been made constantly, and the trends are suggested to continue. On the other hand, other technical categories, such as magnetic circuits of electric motors, are critically innovated recently and intensively along with the increase in attention due to their high potential to improve performance. In addition, obtaining U.S. patents for core technologies, including batteries, battery management systems, electric motors, power electronics, and heat pumps, is crucial to gaining U.S. BEV market share, though it is not the case to succeed in the global market. Furthermore, their patents are not necessarily critical innovations in the technological development of the field. Current trends illustrate that significant BEV innovations are distributed across various entities. This suggests that though patents in the automotive industry have been typically held on verticals, diverse supply chain strategies, including incorporating innovative startups into their own companies or entering into horizontal partnerships with companies that have emerging technologies, are gaining importance in staying competitive in a market where leadership in each technology can swiftly change.