The Spatiotemporal Correlation and Nonlinear Response Mechanism Between New Energy Vehicle Charging Facilities and Urban Spatial Vitality: Based on the ISTNR Model

New energy vehicle (NEV) charging facilities are not only a key support for new transportation infrastructure, but also an important catalyst for reshaping urban spatial functions and vitality. Exploring the nonlinear correlation between their spatial layout and urban vitality is of great significance for optimizing urban spatial structure. This paper takes 2853 districts and counties across the country from 2013 to 2022 as the research object, constructs a multidimensional urban spatial vitality measurement system, analyzes the spatiotemporal evolution characteristics of the two using a coupling coordination degree model, and introduces an integrated spatiotemporal nonlinear regression (ISTNR) model to identify the driving mechanism and interactive effects of spatial vitality factors on charging pile distribution. The results show that: (1) the spatial distribution of charging piles and urban spatial vitality in China exhibit significant “high–high” agglomeration and spatiotemporal coordination characteristics; (2) the coupling coordination degree between the two shows a stable trend, but there is significant regional imbalance, with higher coordination levels in eastern coastal urban agglomerations; (3) the ISTNR model is superior to traditional GTWR and random forest models in dealing with spatiotemporal heterogeneity and nonlinear relationships, and can more accurately depict complex geological processes; (4) urban spatial vitality has a significant nonlinear driving mechanism on charging pile distribution, with factors such as the density of catering, commercial, and medical facilities being the most closely related to charging pile distribution, and there is a clear interactive effect, which has a significant impact on the marginal driving effect of charging pile layout. The research results provide a theoretical basis for the precise planning and spatial quality improvement of urban charging infrastructure.