Corrigendum to “First-Principles Calculation of Contact Electrification and Validation by Experiment” [J. Electrost. 82 (2016) 11]

Understanding the Ferroelectric Polymer–Metal Contact Electrification for Triboelectric Nanogenerator from Molecular and Electronic Structure

“…Furthermore, a comparison of Figure 2b and Figure 2c,d shows after contact with metals, the electron distribution of the internal molecules in the α‐phase PVDF remains unchanged, while the internal molecules in the β‐phase PVDF have the charge redistribution related to the permanent dipole of the polar molecules, which displays a new phenomenon that has not been revealed in the nonferroelectric polymer–metal CE research. [ 16,26–30 ] As for β phase intramolecular charge redistribution (see insets in Figure 2c,d), on the CF bond located at one side of the ‐(C 2 H 2 F 2 ) n ‐ zigzag structure, the strong electronegative atom F is surrounded by the electron enrichment region and the C atom is surrounded by the electron depletion region. On the other side, the CH bond shows the electron enrichment region around the C atom and the electron depletion region around the weakly electronegative atom H. Moreover, the direction of charge transfer within the internal molecular chain is opposite to that between the two material interfaces.…”

“…In addition, we perform the first‐principles calculations to investigate the effect of the interface distance on the charge transfer between ferroelectric polymers and metals, in which the decrease in the interface distance represents the increase in the compression force, as shown in Figure S11 in the Supporting Information. The decrease in the interface distance of the metal–polymer could lead to an increase in the amount of charge transfer, which is related to the overlap degree of the electron cloud of the atoms on the contact surface of the two materials, [ 16,26,27 ] and has nothing to do with the piezoelectric effect of ferroelectric polymers. In summary, when the compression deformation increases, the charge transfer between the polar phase PVDF and Cu is further enhanced through the coupling of piezoelectric and triboelectric effects.…”

Quantum Theory of Contact Electrification for Fluids and Solids

“…As to be expected, first‐principles calculations [and mostly density‐functional theory (DFT)] have been carried out for quantitative studies but do not provide explanations for all observed effects and are currently restricted to periodic solids and elastic electron transfer. [ 20–26 ] Indeed, it is even questionable as to whether they all computed charge transfer. For example, Zhang and Shao [ 22 ] clearly did not since they relaxed a system consisting of both materials—this amounts to bond creation between the two materials and the “charge transfer” they calculated is simply a bond polarity.…”

Tribocharging of granular materials and influence on their flow

“…Several hypotheses have been investigated throughout history to explain this effect and it was first shown that a transfer of electrons could be due to defects in the surface states of the two materials involved in the contact. 7,12,13 A possible transfer of ions 14 or electrostatic discharges in the region between the two objects in contact 15 was also postulated but the charging of different materials by rubbing is still considered as a complex dynamical process involving many different mechanisms. 16 Despite the lack of knowledge on the charging of granular materials, this effect is still often pointed out to provide an explanation to different phenomena such as planet formation by aggregation 17,18 or the migration of dunes at the surface of Mars.…”