Research on the contribution of technological innovation efficiency and internal structure optimization of charging pile industry: A case study of China

In the context of resource scarcity and environmental protection, the new energy industry has garnered significant attention from various sectors. The charging pile (CP) industry, a crucial component of the new energy vehicle (NEV) industry's supply chain, requires improvements in both quantity and quality. This study examined the technological innovation efficiency (TIE) of the CP industry, considering two levels: pure technical efficiency (PTE) and scale efficiency (SE), and explored methods to optimize its internal structure. By combining the grey correlation analysis (GCA) method with the generalized data envelopment analysis (GDEA) model, a reliable evaluation indicator system was established. Empirical findings revealed that the PTE of technological innovation in the CP industry exhibited an upward trend from 2019 to 2022, achieving a GDEA-effective state. However, the SE of technological innovation shows a downward trend, indicating non-GDEA effectiveness. The contribution of CP companies to the PTE of technological innovation has shown a persistent and accelerating decline, while their contribution to SE, once negative, gradually shifts toward a positive influence. Consequently, the internal technological innovation structure of the CP industry necessitates optimization and adjustment to attain balance. This study provides recommendations from the perspectives of both the government and companies.