The 2D MXene-integrated thermoelectric device converts temperature differences into electrical power.
Waste heat is a significant global issue, with about 66% of energy being lost as waste heat during daily energy consumption.[1] Thermoelectric technology offers a promising solution by converting waste heat into electrical power.
Thermoelectric devices, commonly found in commercial products, often use bismuth telluride-based materials to convert temperature differences into electrical energy. In theory, reducing the thermal conductivity (the ability to transfer heat) of thermoelectric materials helps maintain the temperature difference across the devices, thereby enhancing their power generation capacity. However, despite significant efforts to reduce the thermal conductivity of bismuth telluride-based materials, this objective remains challenging due to their efficient heat conduction properties.
One practical approach to lowering thermal conductivity is creating nano-composite structures. These structures scatter the vibrations that carry heat, slowing down heat movement through the material's lattice structure. Recognising the potential of 2D nano-phase materials in enhancing thermoelectric performance, Professor Roy Vellaisamy, Chair Professor of Intelligent Systems at Hong Kong Metropolitan University, and his team, Dr Vaithinathan Karthikeyan, Dr Dani Assi and Dr Hongli Huang, explored the integration of 2D-MXenes into thermoelectric materials. This study, supported by the Research Grants Council's Faculty Development Scheme, aimed to examine the thermoelectric properties of these integrated materials.[2]
The research team designed a thermoelectric generator incorporating 2D MXenes, which improved overall thermoelectric performance by reducing thermal conductivity and enhancing electrical conductivity. This device achieved a maximum power output of 1.14 mW with a power conversion efficiency of 5.4%, surpassing other thermoelectric devices. The power density of this device is 6.1 mWcm−2 (milliwatts per square centimeter), indicating high efficiency in generating power per unit area. Additionally, the device demonstrated robust power generation stability and durability, with resistance and power output changes below 2% and 1%, respectively, after 15 days.
This study paves the way for more efficient waste heat recovery processes. Integrating 2D MXenes into thermoelectric devices, alongside bismuth telluride materials, significantly improves the overall efficiency of these devices. Enhanced thermoelectric performance leads to better conversion of waste heat into usable electrical power. Consequently, this increased efficiency in waste heat recovery not only boosts electricity generation from otherwise wasted heat but also contributes to environmental conservation by reducing energy waste and lowering the overall carbon footprint.
For more details, please refer to the following publication from the research project:
'2D MXene Interface Engineered Bismuth Telluride Thermoelectric Module with Improved Efficiency for Waste Heat Recovery', Advanced Materials Technologies.
[1] L. E. Bell, Science 2008, 321, 1457.
[2] Reference no.: UGC/FDS16/E01/23
