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A demonstration of DTCCs by recovering waste heat from the heated pipe
filled with hot water. Powered by ten DTCCs, the OLED HKU logo lighted up and
the smart window changed color. The OLED is turned off while the smart window
(right) became transparent again when power is disconnected.Dr Tony Shien-Ping
Feng of the Department of Mechanical Engineering at the University of Hong Kong
(HKU) and his team
invented the Direct Thermal Charging Cell (DTCC), which can convert low-grade
heat to electricity.Dr Tony Shien-Ping Feng says the Direct Thermal Charging
Cell (DTCC) can power smart energy devices. Voltage generated from body heat is
able to support major sensors such as health monitoring devices.The DTCC can
harness body heat to power wearable electronic devices or medical devices for
monitoring body health conditions.A demonstration of DTCCs by recovering waste
heat from the heated pipe filled with hot water. Powered by ten DTCCs, the OLED
HKU logo lighted up and the smart window changed color. The OLED is turned off
while the smart window (right) became transparent again when power is
disconnected.Dr Tony Shien-Ping Feng of the Department of Mechanical
Engineering at the University of Hong Kong (HKU) and his team (from left to
right: Wang Xun, Huang Yu-ting and Mu Kai-yu), invented the Direct Thermal
Charging Cell (DTCC), which can convert low-grade heat to electricity.
Dr Tony Shien-Ping Feng of the Department of Mechanical Engineering at
the University of Hong Kong (HKU) and his team invented a Direct Thermal
Charging Cell (DTCC) which can effectively convert heat to electricity,
creating a huge potential to reduce greenhouse effects by capturing exhaust
heat and cutting down primary energy wastage.
The new invention is recently published in the prestigious journal Nature
Communications (http://www.i-nanoeng.com/upload/2019/09/20190918160051.pdf),
and the research has been featured in the Nature Communications Editors’
Highlights webpage. HKU’s Technology Transfer Office has filed for the
invention’s US provisional patent and PCT (Patent Cooperation Treaty) patent.
Low grade heat is abundantly available in industrial processes (80 to
150°C), as well as in the environment, living things, solar-thermal (50 to
60°C) and geothermal energy. Over 60% of the world’s primary energy input,
whether it is in the industrial process or domestic energy consumption, is
wasted as heat. A majority of this loss as waste heat is regarded as low-grade
heat.
The newly designed DTCC is a game-changing electrochemical technology
which can open new horizons for applications to convert low-grade heat to
electricity efficiently. It is a simple system with the basic unit sized only
1.5 sq.cm and thickness 1 to 1.5 mm. The cell is bendable, stackable and low
cost.
DTCC can be used in HVAC (heating, ventilation, and air conditioning)
system to recycle low-grade heat from the compressor and condenser into
electricity for use in electrical devices. It can be integrated with the window
frame to harvest solar thermal energy to power electrochromic windows, or used
as portable devices to power iphones or life-saving equipment in the
wilderness. With the increasing popularity of wearable technology, this system
may one day harness body heat to power wearable electronic devices or medical
devices for monitoring body health conditions like blood sugar levels and blood
pressure.
Dr Feng said: “Efficient low-grade heat recovery can help to reduce
greenhouse gas emission but current technologies to convert this heat to
electricity is still far from optimum. DTCC yields a conversion efficiency of
over 3.5%, surpassing all existing thermo-electrochemical and thermo-electric
systems, which is either too costly or complicated, or too low in efficiency
for everyday applications. DTCC is a revolutionary design with great potentials
in smart and sustainable energy devices.”
The new thermal charging cell uses asymmetric electrodes: a graphene
oxide/platinum (GO/Pt) cathode and a polyaniline (PANI) anode in Fe2+/Fe3+
redox electrolyte via isothermal heating operation without building thermal
gradient or thermal cycle. When heated, the cell generates voltage via a
thermo-pseudocapacitive effect of GO and then discharges continuously by
oxidizing the PANI anode and reducing Fe3+ to Fe2+ under isothermal heating on
cathode side till Fe3+ depletion. The energy conversion works continuously
under isothermal heating during the entire charge and discharge process. The
system can be self-regenerated when cooled down. This synergistic chemical
regeneration mechanism allows the device cyclability.
The team is selected as one of the 16 finalists out of 300 applications
and one of the only two finalists in Hong Kong competing in the Hello Tomorrow
Regional Summit 2019, a competition for start-ups to adapt their research for
real-world commercial uses, which will take place in Singapore this Thursday
(November 7).
The invention has won the Championship in the HKU 2018 DreamCatchers 100K
Entrepreneurship Competition. The team has established a start-up company, High
Performance Solution, which is aided by the Technology Start-up Support Scheme
for Universities (TSSSU). The company also joined the Incu-Tech 3-year
programme at the Hong Kong Science Park and received its first revenue from the
prototypes. The team has participated in the first X-plan roadshow of Talent
Development Forum in Great Bay Area held by the Hong Kong X Foundation. It has
also taken part at the Entrepreneurship Forum in Bahrain, Middle East.
