Abstract
Low-grade heat energy recycling is the key technology of waste-heat utilization, which needs to be improved. Here, we use a zinc-assisted solid-state pyrolysis route to prepare zinc-guided 3D graphene (ZnG), a 3D porous graphene with the interconnected structure. The obtained ZnG, with a high specific surface area of 1817 m2·g−1 and abundant micropores and mesopores, gives a specific capacitance of 139 F·g−1 in a neutral electrolyte when used as electrode material for supercapacitors. At a high current density of 8 A·g−1, the capacitance retention is 93% after 10,000 cycles. When ZnG is used for thermally chargeable supercapacitors, the thermoelectric conversion of the low-grade heat energy is successfully realized. This work thus provides a demonstration for low-grade heat energy conversion.
Highlights
In response to the climate crisis, major economies have announced their own plans
Owing to the principle of the energy storage mechanism based on the electric double layer, carbon materials show a positive correlation between the specific capacitance and the specific surface area when applied to supercapacitors [21,22,23]
Cheap and readily available glucose was used as the carbon source, and the low-boiling zinc powder was used as the tiering agent
Summary
In response to the climate crisis, major economies have announced their own plans. In its actual implementation, efficient use of existing energy is very important [1,2,3,4,5,6]. According to different principles and devices, there are two main types of low-grade thermal energy utilization, i.e., thermocells and thermally chargeable supercapacitors (TCSs) [10,11,12]. Owing to the principle of the energy storage mechanism based on the electric double layer, carbon materials show a positive correlation between the specific capacitance and the specific surface area when applied to supercapacitors [21,22,23]. Our group has developed a unique method for preparing zinc-guided 3D graphene (ZnG) via a zinc-assisted solid-state pyrolysis (ZASP) route [28] In this method, zinc with a low boiling point (907 ◦C) is used as the tiering agent, and glucose is used as the carbon source. The thermoelectric conversion of the low-grade heat energy is realized
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
