Olsen Martin, Örtegren Jonas, Zhang Renyun, Reza Salim, Andersson Henrik, Olin Håkan
Department of Natural Sciences, Mid Sweden University, Sundsvall, 851 70, Sweden.
Department of Electronics Design, Mid Sweden University, Sundsvall, 851 70, Sweden.
Sci Rep. 2018 Mar 28;8(1):5293. doi: 10.1038/s41598-018-23666-y.
The triboelectric effect, charging by contact, is the working principle in a device called a triboelectric nanogenerator. They are used as efficient energy transducers in energy harvesting. In such generators the charging of surfaces at contact is followed by a separation of the surfaces increasing the electrical energy which can subsequently be used. Different materials have different triboelectric potentials leading to charging at contact. The temperature dependence of the charging has just recently been studied: the triboelectric effect is decreasing with temperature for a generator of Al-PTFE-Cu. Here, we suggest a mechanism to explain this effect assuming ion transfer using a two-level Schottky model where the two levels corresponds to the two surfaces. The difference in binding energy for ions on the two surfaces then enters the formula for charging. We fit the triboelectric power density as a function of temperature obtained from a two-level Schottky model to measured data for nanogenerators made of Al-PTFE-Cu found in three references. We obtain an average separation energy corresponding to a temperature of 365 K which is of the right magnitude for physically adsorbed atoms. We anticipate that this model could be used for many types of triboelectric nanogenerators.
摩擦电效应，即通过接触起电，是一种名为摩擦纳米发电机的设备的工作原理。它们在能量收集方面被用作高效的能量转换器。在这种发电机中，接触时表面充电之后是表面分离，从而增加电能，随后电能便可被利用。不同材料具有不同的摩擦电势，导致接触时起电。最近人们研究了充电的温度依赖性：对于铝 - 聚四氟乙烯 - 铜的发电机，摩擦电效应随温度降低。在此，我们提出一种机制来解释这种效应，假设使用双能级肖特基模型进行离子转移，其中两个能级对应两个表面。两个表面上离子结合能的差异随后进入充电公式。我们将从双能级肖特基模型得到的摩擦电功率密度作为温度的函数，拟合到在三篇参考文献中找到的由铝 - 聚四氟乙烯 - 铜制成的纳米发电机的测量数据。我们得到对应于365K温度的平均分离能，对于物理吸附原子来说，这个量级是合适的。我们预计这个模型可用于多种类型的摩擦纳米发电机。
