Visualizing technology topics on recycling power battery: A perspective of BERTopic and entropy weight

The rapid expansion of electric vehicles has led to a surge in retired power batteries, posing significant challenges for resource recovery and environmental sustainability. However, existing studies lack a systematic and quantitative framework to identify key technologies and evaluate patent value in this domain. This study hypothesizes that integrating topic modeling with multi-dimensional patent evaluation can effectively reveal technological evolution patterns and identify high-value core patents. Methodologically, we employ BERTopic to extract and track dynamic technological topics from global patent data and construct a patent technology value evaluation system using an entropy-weight method based on eight indicators. The results show that China leads in patent quantity but lags behind the United States and Japan in average patent value, with high-value patents concentrated in system-level metallurgical and material regeneration technologies rather than process-level optimizations. This study contributes a novel integrated analytical framework and provides targeted insights for fostering high-value innovation and optimizing technological pathways in the power battery recycling industry. • A BERTopic and patent value analysis reveals key tech trends in EV or power battery recycling. • Global R&D hotspots on recycling power battery are similar, but China and other countries differ in technical pathways. • Provides policy insights for China to improve technology quality and regulatory frameworks.