The capacitive performances of carbon obtained from the electrolysis of CO2 in molten carbonates: Effects of electrolysis voltage and temperature

Electrochemical Production of Sustainable Hydrocarbon Fuels from CO2 Co-electrolysis in Eutectic Molten Melts

“…Recently, the use of solid oxide electrolysis cells (SOECs) has gained much interest in the preparation of syngas (CO + H 2 ), hydrogen, or methane gas from the CO 2 –H 2 O coelectrolysis. , However, certain limitations such as low production rate, specific electrode materials, higher production costs, lower durability, and high energy utilization became the reason for their rejection on industrial-scale implementation . Molten salts exhibit the same chemistry regarding CO 2 and H 2 O reduction as in SOECs except that CO 2 can also be reduced to carbon in addition to carbon monoxide depending on the operating conditions, which can thereby affect the products. The deposited carbon on cathode can facilitate the formation of different kinds of hydrocarbons (rather than CO) in the case of molten salt electrolysis.…”

Molten Salt Electrolytic CO2-Derived Carbon-Based Nanomaterials for Energy Storage and Electrocatalysis: A Review

“…48 Through optimization of experimental parameters, including raising cell voltages to 4.5 V and decreasing operating temperatures to 450 °C, the specific capacitance of the CO 2 −C can be elevated to as high as 550 F g −1 (0.2 A g −1 ). 51 In addition, the performances of symmetrical full supercapacitors have also been studied. A hollow carbon sphere synthesized by constant-voltage electrolysis in 2 mol % CaCO 3 -containing LiCl−KCl at 450 °C for 1 h derived a specific capacitance of 171 F g −1 at 0.2 A g −1 in 6 M KOH when assembled as a symmetrical full supercapacitor.…”

“…For instance, amorphous carbon powder synthesized from a melt of Li 2 CO 3 –Na 2 CO 3 –K 2 CO 3 (at 500 °C) by employing a Ni cathode and a SnO 2 anode (cell voltage: 4.0 V) exhibits a remarkable Brunauer–Emmett–Teller (BET) surface area exceeding 400 m 2 g –1 and demonstrates a specific capacitance of 400 F g –1 (0.2 A g –1 ) in a 1 M H 2 SO 4 aqueous solution . Through optimization of experimental parameters, including raising cell voltages to 4.5 V and decreasing operating temperatures to 450 °C, the specific capacitance of the CO 2 –C can be elevated to as high as 550 F g –1 (0.2 A g –1 ) . In addition, the performances of symmetrical full supercapacitors have also been studied.…”

Sustainable Carbons and Fuels: Recent Advances of CO2 Conversion in Molten Salts

“…The electrolytic carbons from CO 2 , due to their diversified structures, abundant morphologies, highly active surface, excellent electrical conductivity and good chemical stability have been investigated as active electrodes in both supercapacitors and batteries [5,13a,b,22a,37d,46,47,57] . The CO 2 ‐derived carbons exhibited excellent capacitive performance in both H 2 SO 4 and KOH aqueous solutions, and delivered a specific capacitance from 171 to 550 F g −1 at 0.2 A g −1 [5,22a,46,47,57a] . For example, amorphous carbon powder synthesized from 500 °C Li 2 CO 3 −Na 2 CO 3 −K 2 CO 3 melt using Ni anode and SnO 2 cathode (4.0 V cell voltage) has a high BET surface area of more than 400 m 2 g −1 , and exhibits a specific capacitance of 400 F g −1 at 0.2 A g −1 in 1 M H 2 SO 4 aqueous solution [22a] .…”

“…For example, amorphous carbon powder synthesized from 500 °C Li 2 CO 3 −Na 2 CO 3 −K 2 CO 3 melt using Ni anode and SnO 2 cathode (4.0 V cell voltage) has a high BET surface area of more than 400 m 2 g −1 , and exhibits a specific capacitance of 400 F g −1 at 0.2 A g −1 in 1 M H 2 SO 4 aqueous solution [22a] . By optimizing the experimental conditions including the cell voltages (4.5 V) and operating temperatures (450 °C), the specific capacitance of the carbon can reach as high as 550 F g −1 at 0.2 A g −1 [57a] . It is found that the molten electrolysis conditions affected the carbon structures and thus the supercapacitive performance.…”