From Liquid–Solid Contact Electrification to Triboelectric Nanogenerators: Mechanism, Methods and Applications

ABSTRACT The liquid–solid triboelectric nanogenerator (LS‐TENG) can efficiently convert low‐frequency, unstable ocean wave, droplet energy into electricity. Additionally, it holds the potential to function as a self‐powered sensor for liquid physicochemical composition analysis. Herein, we summarize recent advances on the principles, method, and application of LS‐TENG. Firstly, we introduced the fundamental principles of liquid–solid contact electrification and the electrical double layer. Second, we highlighted the strategies for enhancing the output of LS‐TENG in terms of material selection, modification, and structural optimization. These strategies encompass the regulation of solid triboelectric materials, optimization of liquid polarity and ion concentration, and innovative designs. Furthermore, we showcased the latest applications of LS‐TENG in areas such as blue energy harvesting, contact electro‐catalysis, smart interconnection, and physical/chemical/biological signal sensing. Finally, the challenges faced by LS‐TENG, including understanding its mechanisms, material selection, structural innovation, and the expansion of application scenarios are proposed. This work anticipates future trends‐including the development of high‐efficiency energy management, hybrid energy systems with higher energy density, deep interdisciplinary fusion with artificial intelligence, microfluidics, biomedicine, and the establishment of unified international standards and testing protocols, thereby providing targeted and actionable insights for advancing the design optimization, functional expansion, and industrial commercialization of high‐performance LS‐TENG.