Growth of 3D SnO₂ nanosheets on carbon cloth as a binder-free electrode for supercapacitors

Abstract

A three-dimensional (3D) lamellar SnO2 is grown on carbon cloth (CC) substrate (donated as 3D lamellar SnO2/CC) through hydrothermal reactions and subsequent thermal treatments. The resulting 3D lamellar SnO2/CC can be directly used as electrode of supercapacitors with no need for addition of either binder or conductive species, and achieve a specific capacitance as high as 247 F g -1 at a current density of 1 A g -1 within a potential window ranging from -0.6 to 0.3 V because of the unique porous structure accessible to electrolyte ions. In order to match the capacitive behaviors of 3D lamellar SnO2/CC in the two-electrode systems, reduced graphene oxide/carbon cloth (rGO/CC) is prepared by starting from GO. The rGO/CC and 3D lamellar SnO2/CC are respectively used as positive and negative electrode to assemble asymmetric supercapacitor. The device exhibits not only an excellent cycle stability (76.9 % after 10000 cycles at 3 A g -1 ), but also high energy density of 22.8 Wh kg -1 at the power density of 850 W kg -1 under a cell voltage of 1.7 V. Moreover, the as-fabricated supercapacitor has green and environmentally friendly features because aqueous neutral electrolyte is employed in it.

Flexible Binder‐Free CuS/Polydopamine‐Coated Carbon Cloth for High Voltage Supercapacitors

“…At various rates, the energy densities ranges from 48.3 to 26.1 Wh kg −1 with corresponding power densities of 744 to 6919 W kg −1 . These values are significantly higher and/or comparable to other previously reported ASCs, such as CuS nanoparticles//AC ( E =17.7 Wh kg −1 , P =504 W kg −1 ), CuS microspheres//AC ( E =15.1 Wh kg −1 at P =330 W kg −1 ), SnO 2 //RGO ( E =22.8 Wh kg −1 at P =850 W kg −1 ), CuS/3DG//3DG ( E =5 Wh kg −1 at P =450 W kg −1 ), Co 9 S 8 //AC ( E =31.4 Wh kg −1 at P =200 W kg −1 ), and CoS//AC ( E =5.3 Wh kg −1 at P =1800 W kg −1 ) …”

Asymmetric All‐Metal‐Oxide Supercapacitor with Superb Cycle Performance

“…The corresponding Ragone plot for the as-fabricatedA SC is shown in Figure6g. The RGO/SnO 2 //RGO/ MoO 3 ASC with an operating voltage of 1.8 Vs howed an energy density of 33 Whkg À1 at ap ower density of 896 Wkg À1 .M ore importantly,w hen the powerd ensity was increasedt o3 7.5 kW kg À1 ,t he energy density of the ASC was still 13.8 Whkg À1 ,s uggesting that it could provideh igh power density and high energy density concurrently.I na ddition, the energy density of our ASC is comparable to those of other SnO 2 -based and MoO 3 -basedA SCs, [48,[52][53][54][55][56] including SnO 2 / MnO 2 //SnO 2 /p olypyrrole( 27.2 Whkg À1 ,8 50 Wkg À1 ), [52] rGO/ CC//SnO 2 /CC (22.8 Whkg À1 ,8 50 Wkg À1 ), [48] AC// polypyrrole@-MoO 3 (12 Whkg À1 ,3kW kg À1 ), [53] and MnO 2 @rGO//MoO 3 @rGO (25.2 Whkg À1 ,72.8 Wkg À1 ). [54] The cycling stability was furthere valuated in the voltage window 0-1.8 Vatah ighc urrent density of 5Ag À1 ,a sd epicted in Figure 6h.T he RGO/SnO 2 //RGO/MoO 3 ASC retained 92.5 %o fi ts initial capacitance after 20 000 cycles,d emonstrating good cycling stability.…”

“…Such an SnÀ OÀCb ond between SnO 2 and RGO is further corroborated by the C1 ss pectra ( Figure S1) and the Fourier-transform infrared (FTIR) spectra.A si ndicated in Figure 2i,t he characteristic bands detected at 575 and 656 cm À1 correspond to SnÀOÀH and SnÀOÀSn vibrations of SnO 2 ,r espectively. [48] The absorption bands of RGO centereda t1 050, 1158, and 1459 cm À1 can be attributed to the CÀOÀCv ibration of epoxy,t he CÀOv ibration of CÀOH, and an OÀHd eformation vibration, respectively. [39,40,49] After the growth of SnO 2 nanoparticles, the CÀOÀC peak at 1050 cm À1 and the OÀHp eak at 1459 cm À1 disappeared, and the peak corresponding to the CÀOH group at 1158 cm À1 shiftedt o1 180 cm À1 .T hese resultsi ndicateb ond breaking of the epoxy CÀOa nd hydroxyl CÀOH groups with the formation of SnÀOÀCb onds between SnO 2 nanoparticles and RGO.…”

Contribution of Cations and Anions of Aqueous Electrolytes to the Charge Stored at the Electric Electrolyte/Electrode Interface of Carbon-Based Supercapacitors

“…for increasing the pseudocapacitive contribution; [22][23][24][25] (iii) Coating the carbon fibers by other carbon materials such as carbon nanotubes or graphene providing an additional capacitance; [26][27][28][29][30][31][32][33][34][35] (iv) Coating the carbon fibers by several oxides that contribute with an additional pseudocapacitance; the coating can be obtained by chemical deposition, [36][37][38][39][40][41][42][43][44] electrochemical deposition [45][46][47] or printable procedures. 48 …”