1. Dual-band electrochromic smart windows

Dual-band electrochromic smart windows are a recent technology which can notably reduce the building energy consumption via the dynamic and independent control of near-infrared and visible light transmittance. High cost, complex synthesis of the electrochromic material, and inadequate application performance are the current technical challenges in the development of dual-band electrochromic smart windows. Our research interest is the design and synthesis of tuable plasmonic semiconductor nanocrystals that can alleviate the current materials issues in the application of dual-band electrochromic smart windows.

Fig.  The optical transmittance spectra (A) and solar energy transmittance spectra (B) under different applied potential between 4V-2V (vs Li/Li⁺). (C)The photos of films on ITO glass.

2. Rechargeable metal-air batteries

Our main interest here is the design of the rechargeable air electrodes for use in acidic, alkaline, and neutral aqueous electrolytes. The sluggish oxygen electrochemical reactions are the performance-limiting factor in the present state of technology development. Effective oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) catalysts are essential and our emphasis is on the design of low-cost noble-metal free alternatives for large-scale deployment

Fig. Our typical catalysts for the ORR and OER.

3. Lithium-sulfur batteries

Rechargeable lithium-sulfur batteries have drawn intense research interest because of the high theoretical capacity of the sulfur cathode. The development of lithium-sulfur batteries is however met with several technical challenges. The most challenging of them is the dissolution of the sulfur cathode as soluble polysulfides and subsequent shuttling of the latter between the cathode and anode. We have developed several techniques in containing the problem: the development of cathode catalysts to promote the conversion of soluble lithium polysulfides to insoluble products, cathode interlayer design, and operating the Li-S batteries as redox-targeting flow batteries.

Fig. Schematic of the synthesis of the MoS_2-x/rGO composite and the conversion of Li₂S_x on the MoS_2-x/rGO surface.

4. Other research interests

Heterostructured metal nanocrystals. Biological and biommmetic synthesis of metal nanoparticles. Electrochemical mitigation of membrane fouling. Emerging electrical and thermal energy storage materials.