The storage of solar energy in electrochemical energy storage devices is an effective method to solve the intermittent supply of solar energy and realize its wide application. The traditional method is to connect the solar cells with the energy storage device through long wires, and the introduction of long wires leads to ohmic loss. Thus, reducing the conversion and storage efficiency of solar energy. Designing and preparing high-efficiency (optical) electrical functional electrode materials is the key to developing and constructing a simple two-electrode system device to obtain efficient and low-cost photo-assisted electrochemical energy storage devices.
Under the support of the National Natural Science Foundation of China, the Strategic Pilot Science and Technology Project of the Chinese Academy of Sciences, and the Key Laboratory of Nano and Assembly of the Chinese Academy of Sciences, the Wang Zhibing Group and the Yuan Daqiang Group of the Institute of Material Structure of the Chinese Academy of Sciences reported a use of both light. Bifunctional materials for absorption and reversible electrochemical energy storage, a new method for directly converting solar energy into electrochemical energy. First, by Yan Yanzhen, associate researcher of Yuan Daqiang, he synthesized naphthalene diimide (NDI) and triphenylamine (TPA). Unit-linked covalent organic framework material (NT-COF). NT-COF is characterized by filling two-dimensional porous nanosheets with a high specific surface area of 1276 m2/g. Dr. Lu Jiangquan of Wang Yaobing's research group conducted detailed photochemistry/ The electrochemical characterization reveals the efficient intramolecular charge transfer from TPA to NDI unit in NT-COF and the highly reversible electrochemical reaction of the material. NT-COF is the cathode material of lithium ion battery, and the charging voltage is reduced under illumination. 0.5 V, the discharge voltage is increased by 0.5 V, and the efficiency of the entire battery is increased by 38.7%, achieving efficient use of solar energy. This work has reversible electrochemistry at the same time. And bifunctional cathode material should intramolecular charge transfer synergy was designed based on a new type of solar energy - electrochemical energy conversion / storage system, provides a new way for alternative integrated solar batteries and battery systems.
The first author of the article is Lu Jiangquan, the first author is Tan Yanzhen, and the research results are published in the German Applied Chemistry (Angewandte Chemie International Edition, DOI: 10.1002/anie.201806596).
Figure: Schematic diagram of the structure of covalent organic framework materials; Right: Schematic diagram of photo-assisted lithium-ion battery
