Preparation And Electrochemical Properties Of Porous Carbon Nanosheets From Anthracene For Supercapacitor

With the exploration and development of energy storage components,well-characterized elements are getting more and more interest.Supercapacitors?SCs?have been re-emphasized for their outstanding performance.The porous carbons?PCs?as SCs electrode materials?EMs?show good electrochemical performance.Because,firstly,the well-developed pore structure in PCs provides convenient channel for ion transport.Secondly,a large S_BET supplies more active sites for ion adsorption.Thirdly,the excellent conductivity is beneficial for the fast transfer of electrons.At present,there are many studies on the preparation of EMs using chemical by-products such as petroleum asphalt,coal tar pitch,and other macromolecular aromatic compounds as carbon sources.Here,the PCs were obtained from anthracene using different templates,e.g.sheet-like nano-MgO and Mg?OH?₂,coupled with KOH activation.The main results are as below:?1?The sheet-like porous carbons?SPCs?were obtained by using sheet-like nano-MgO as template coupled with in-situ activation of KOH.The SPC₉₀₀ were obtained from 6 g anthracene,9 g nano-MgO,and 18 g KOH,with the activation temperature of 900^oC,exhibits the best overall performance among the all samples.The SPC₉₀₀ features a big S_BET up to 2343 m² g^-1.The specific capacitance of SPC₉₀₀is 268 F g^-1 at 0.05 A g^-1 an still remains 204 F g^-1 at 20 A g^-1,reaching 76.12%retention rate,which presents a highlighted rate performance.The SPC₉₀₀ have superior cycle stability with 98.32%of initial capacitance after 10000 cycles.?2?The corrugated porous carbons?CPCs?were synthesized by using low-cost flake-like Mg?OH?₂ as template.The Mg?OH?₂ starts to decompose into MgO and H₂O at 310^oC,and finished at 550^oC completely.The formed MgO and H₂O would act as template and physical activating agent,respectively.The CPC_3-900 was made when the mass ratio of KOH and anthracene is 3 with the activation temperature of900^oC.The CPC_3-900 has the largest S_BET of 2528 m² g^-1.The average pore size and the pore volume of CPC_3-900 is 2.48 nm and 1.45 cm³ g^-1,respectively.The specific capacitance of CPC_3-900 reached 302 F g^-1 at 0.05 A g^-1,with 73.42%capacitance retention at 20 A g^-1.The CPC_3-900 showing outstanding sustained cycling performance with 97.12%of initial capacitance after 10000 cycles.?3?On the basis of?2?,the nitrogen-doped porous carbons?NLPCs?were prepared by using NH₃ as carrier gas with keeping the same raw materials.The as-made NLPC₃ possesses a high S_BET of 2018 m² g^-1 when the mass ratio of KOH and anthracene is 3.The XPS test showed that the NLPCs contained abundant oxygen-and nitrogen-containg groups.The specific capacitance of NLPC₃ is 363 F g^-1 at 0.05 A g^-1.And still have 253 F g^-1 at 20 A g^-1.The prominent electrochemical performance shows that the NPLCs are suitable for EMs of energy storage components.