Tuning the Wettability of Vertically Aligned CNT–TiO₂ Hybrid Electrodes for Enhanced Supercapacitor Performance

Abstract

Boosting the energy density of carbon‐based materials is of great importance for developing supercapacitors with high cyclic stability. Chemical vapor deposition (CVD) growth of vertically aligned carbon nanotube (VACNT) forest is reported with millimeter height on Si/SiO2 substrate and engineer its microstructure and wettability for remarkable supercapacitor performance. A simple method to alter the microstructure of VACNT forest by adding small amount of ethanol in KOH electrolyte is demonstrated. The modified electrolyte facilitates the formation of pores and channels in CNT forest and leads to increased active surface area. Microstructure‐engineered CNT forest is further coated conformally with 3 nm of TiO2 using atomic layer deposition. The developed VACNT‐TiO2 hybrid shows 102‐fold increase in energy density, 20‐fold increase in specific capacitance, and 13‐fold increase in power density along with high capacitive retention as compared to bare VACNT in KOH. This improved performance is correlated to formation of micro channels that enable more accessible surface area for electrolytic ions. The demonstrated simple electrolyte engineering approach with increased energy density of aligned CNT‐TiO2 hybrid is relevant for portable energy storage applications.

Aerosol-Jet-Printed CoFe2O4 Nanoparticle − Vertically Aligned Carbon Nanotube Composite for Microsupercapacitors

“…Other literature studies have also shown increased electrochemical performance because of increased wettability from the CNT composite, such as TiO 2 −CNT and polypyrrole-CNT. 29,30 Thus, the effect of the coating increasing wettability certainly contributes to the improved performance of the CoFe 2 O 4 -VACNT composite.…”

Low temperature synthesis of crystalline pyrite FeS2 for high energy density supercapacitors

“…As is well documented in the literature, the wettability of the electrode surface directly influences the formation of the electrical double layer, and consequently, determines its capacitive charge storage capability. [20][21][22] Therefore, the superior performance of the FeS 2 SCs is probed by measuring the contact angles of the FeS 2 electrode with respect to TEABF 4 and EMIM-BF 4 electrolytes. Fig.…”

Ultrahigh‐Areal Capacitance Flexible Supercapacitors Based on Laser Assisted Construction of Hierarchical Aligned Carbon Nanotubes

“…[1] Based on the GCD curves, the areal capacitance of the hierarchical VACNTs electrode are calculated by formula (3) and the value is ≈1300 mF cm −2 , which is higher than most reported carbon-based SCs (Table 1). [13,[22][23][24][25][26][27][28][29][30][31][32][33][34][35] In addition, the specific capacitance can also be obtained by means of CV curve integration, namely Equation (4).…”