The research and development of electrochemical energy conversion and storage devices, including primary and secondary batteries, super-capacitors, fuel cells and dye-sensitized solar cells (DSSC), are of significance for easing the energy crisis and raising living standards. The environment-friendly, low-cost and high-efficiency electrolyte plays an important role in promoting technical progress of these devices.
Teaming up with FU Zhenghong from Fudan University in Shanghai, a research team led by MENG Qingbo and LI Hong from the National Laboratory for Condensed Matter Physics at the CAS Institute of Physics has been successful in developing two energy conversion and storage devices: a DSSC using an AlI3-ethanol electrolyte and a new Al/I2 primary battery, which are noted for their low production costs and environmental benignity. These feats, which have been reported in a recent issue of the Journal of American Chemistry Society, have been filed for three invention patents.
The researchers have produced a new electrolyte -- AlI3-ethanol electrolyte -- simply by adding aluminum powder and iodine into ethanol at ambient conditions. A DSSC using this electrolyte could achieve an energy conversion efficiency of 5.9% at AM 1.5 (100 mW/cm-2). This is comparable to the DSSC using a conventional LiI-nitrile electrolyte, which usually use expensive anhydrous LiI and noxious solvents.
In the Al/I2 battery they have developed, AlI3 is formed spontaneously when aluminum and iodine electrodes are brought into contact at room temperature. Compared with the conventional Li/I2 battery, the new cell can supply a large discharge rate with discharge current density. The low cost of the Al/I2 system as well as the feature of environmental friendliness makes this system as an attractive device for electrochemical energy conversion and storage. The researchers believed that their work on AlI3 electrolyte, based on iodide transport, can also find other applications.
Their work has been supported by the National High-tech Research, Development Programs and National Program on Key Basic Research Projects and the CAS Bairen (or "100-talent") Program.