Micro-Supercapacitors Based on Termination Optimized MXene Quantum Dots with Ultra-High Rate Capability and Fast Frequency Response

Micro-supercapacitors (MCs) are miniaturized energy storage devices that can enhance the performance of wearable health devices, medical implants, wireless sensors, and micro-electromechanical systems due to their fast frequency response, long life cycle, and vast temperature operation. However, to make these MC systems into commercially feasible products, necessary improvements to current MC performance are necessary, primarily in increasing the energy density. Reducing the electrode materials’ dimension is the most effective approach to boost the performance of MCs. Graphene quantum dots (QDs) have already shown improved response over conventional MCs. This work aims to develop QDs from MXene, a class of layered transition metal carbides, carbonitrides or nitrides. These MXene QDs will increase the energy density of MCs by twofold and optimize their electrochemical performance for commercial viability. MXene of an optimized size for QDs will be produced using environmentally friendly etching methods. MXene QDs with different terminations will then be prepared and used as electrodes to fabricate MCs and to evaluate the capacitance and stability. Density Functional Theory (DFT) methods will be used to examine the physical properties of the materials and further understand the experimental results. The MCs that display the best performance will be assembled to study their characteristics further. The research will provide a green synthesis protocol of MXene and accelerate the discovery of optimized MXene QD materials. Moreover, the MXene QD MC devices will have increased energy storage performance and durability, ideally suited for the next generation of wearable health devices and clean energy storage.

Figure 1. Aiping Yu, Professor and University Research Chair. She is the recipient of the prestigious NSERC Steacie Fellowship and RSC Rutherford Medal, as well as listed in the 2022 World’s Top 2% Scientist database published by John Ioannidis at Stanford. Her research mainly focuses on 2D and carbon nanomaterials synthesis and surface tailoring for various applications, including supercapacitors, batteries, CO2 reduction, and polymer composites for EMI shielding and anti-corrosion.