Nano‐engineered Diamond‐based Materials for Supercapacitor Electrodes: A Review

Abstract

Owing to the popularity of carbon‐based supercapacitors, diamond has been examined as a potential candidate for such devices with unique advantages such as a wide electrochemical potential window and stable capacitive behavior in both aqueous and non‐aqueous electrolytes. Moreover, its chemical stability in harsh environments at extreme applied potentials and currents provides unique opportunities for designing new supercapacitors. Owing to the intrinsic low surface area of diamond, it is necessary to increase the electrochemically active surface area or to produce diamond‐based composites, thereby ensuring capacitance improvement for the practical applications. According to previous literature reports, nano‐engineered diamond structures can achieve a specific capacitance values as high as 10 mF cm−2 with a specific energy of 10–100 Wh kg−1 in aqueous electrolyte. The present manuscript reviews the recent advances in this topic of research by highlighting the potentials and challenges of diamond‐based supercapacitors. Special attention is paid to the fabrication methods and electrochemical performance of particular material combinations in view of further application for supercapacitor construction.

Diamond Supercapacitors: Towards Durable, Safe, and Biocompatible Aqueous-Based Energy Storage

“…Diamond – particularly boron or nitrogen doped conductive diamond – has been viewed favorably as a supercapacitor electrode material primarily for its potential to address this issue, possessing a wide electrochemical potential window of up to 3.5 V in aqueous electrolyte to allow higher operation voltages ( Gao and Nebel, 2016 ; Yu et al, 2017 ; Wang et al, 2020a ). While diamond is not yet widely employed due to the relatively high cost and difficulty in processing ( Siuzdak and Bogdanowicz, 2018 ; Yu et al, 2021 ), it nevertheless has attracted interest for its wide potential window and other excellent properties. For example, diamond is durable and biocompatible, making it suitable for long-term biomedical applications such as high capacitance neural interfaces ( Hébert et al, 2014 ; Garrett et al, 2016 ; Tong et al, 2016 ; Siuzdak and Bogdanowicz, 2018 ; Wang et al, 2020a ; Falahatdoost et al, 2021 ).…”

High-performance supercabatteries using graphite@diamond nano-needle capacitor electrodes and redox electrolytes

“…With respect to the capacitor electrode, conductive diamond synthesized using the chemical vapor deposition (CVD) technique possesses a variety of desirable features for such a goal. [9][10][11] It is mechanically stable and chemically inert and exhibits outstanding chemical stability in harsh environments or under extreme conditions (e.g., at high current densities and potentials). Diamond supercapacitors are thus expected to be steady for longer cycle life than those fabricated from other materials.…”

Great Variety of Man-Made Porous Diamond Structures: Pulsed Microwave Cold Plasma System with a Linear Antenna Arrangement

“…Using the bottom-up approach, porosity of the diamond films is achieved by either (i) employing geometrically prestructured substrates (i.e., templated growth) or (ii) optimized chemical vapor deposition (CVD) by providing suitable growth conditions (mainly by varying the gas mixture). The variety of supporting substrates includes fully or partially transformable polymers, 19−21 various non-carbon-based templates, 14,17,22,23 carbon-based templates, 24−28 or SiO x -based templates. 29−31 The important advantage of templated diamond growth is that the porosity is generally guided by the template that is used.…”