First theoretical triboelectric series*

From the early stage of planet formation due to charging between dust particles to state-of-art triboelectric nanogenerator, triboelectricity has been present nearby the history of the earth and remained an unprecedented unresolved problem. Here, we introduce the rigorously formulated theoretical triboelectric series based on the thermoelectric effect. Our work suggests the first theoretical quantitative triboelectric series, determined by triboelectric factors defined as Seebeck coefficient, density, specific heat, and thermal conductivity. We have revealed that the dissipation of frictional energy forms a temperature distribution in material and thus creates an electrostatic potential difference at the interface, which initiates charge transfer. Our findings are expected to deepen not only the microscopic understanding of triboelectricity but also provide an effective strategy to increase the efficiency of triboelectric nanogenerators.