Prospects of battery assembly for electric vehicles based on patent analysis

Abstract

The ceiling of energy density of batteries in materials level motivates the innovation of cell, module and pack that constitute the battery assembly for electric vehicles (EVs). Patent analysis is a powerful means to inform technology life cycle and forecast upcoming innovations. To date, only a handful of research have quantitatively analysed and compared battery assembly in the EV field, resulting in a lack of information to discern the battery layout. Herein, battery patents are categorized into cell, module and pack levels, and are recorded with a function of timeline and technology life cycle to identify their development status. It indicates the maturity stage of the cell level while noting the growth stage of module and pack levels, which probably results from the intensive demand of large-size and high-quality batteries for EVs. Moreover, the global patent distribution reveals that China and Japan possess most patents among cell, module and pack levels, and that patent assignees are scattered in China, whereas concentrated in Japan and Korea. This work is expected to figure out the battery technology trends to construct energy-dense batteries in the EV field, as well as provide instructive information for decision-makers to lay out battery technologies in the future.