Advanced Studies on High-Performance Metal-Ion Capacitors: Technologies, Systems and Applications

Dear Colleagues,

Metal-ion capacitors as newly developed hybrid electrochemical energy storage (EES) systems are composed of a battery-type electrode and supercapacitor-type electrode, coupled with the redox reaction and electric double layer behavior, which could achieve the desired peculiarities of a high energy density, large power density and long lifespan.  However, due to the incompatibleness of two different energy storage mechanisms, the electrochemical performances are unsatisfactory. Moreover, the construction of advanced metal-ion capacitors is mainly limited by key bottlenecks such as the kinetics mismatching between electrodes, unclear storage mechanism of electrodes and uncontrollable pre-metalation technology. To address these concerns, this edition discusses the technologies, systems and applications of metal-ion capacitors.

Topics of interest include but are not limited to:

• Energy storage mechanism of metal-ion capacitors;
• Key technologies of metal-ion capacitors;
• Pre-metalation methods;
• Electrolytes;
• Advanced characterizations for metal-ion capacitors;
• Cell structure designs.

Dr. Kangyu Zou
Dr. Tianjing Wu
Dr. Jiangmin Jiang
Guest Editors

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• lithium-ion capacitor
• sodium-ion capacitor
• potassium-ion capacitor
• electrode materials
• energy storage mechanism
• pre-metalation
• electrolytes

Title: Biomass-Derived Carbon Materials for Advanced Metal-Ion Hybrid Supercapacitors: A Step Towards More Sustainable Energy
Authors: Syed Shaheen Shah
Affiliation: Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8520, Japan
Abstract: Modern research has made the search for high-performance, sustainable, and efficient energy storage technologies a main focus, especially in light of the growing environmental and energy-demanding issues. This review paper focuses on the pivotal role of biomass-derived carbon (BDC) materials in the development of high-performance metal-ion hybrid supercapacitors (MIHSCs), specifically targeting sodium (Na), potassium (K), aluminium (Al), and zinc (Zn) ion-based systems. Due to their widespread availability, renewable nature, and exceptional physicochemical properties, BDC materials are ideal for supercapacitor electrodes, which perfectly balance environmental sustainability and technological advancement. The paper delves into the synthesis, functionalization, and structural engineering of advanced biomass-based carbon materials, highlighting the strategies to enhance their electrochemical performance. It elaborates on the unique characteristics of these carbons, such as high specific surface area, tunable porosity, and heteroatom doping, which are pivotal in achieving superior capacitance, energy density, and cycling stability in Na, K, Al, and Zn ion hybrid supercapacitors. Furthermore, the compatibility of BDCs with metal-ion electrolytes and their role in facilitating ion transport and charge storage mechanisms are critically analyzed. Novelty arises from a comprehensive comparison of these carbon materials across metal-ion systems, unveiling the synergistic effects of BDC's structural attributes on each supercapacitor type performance. This review also casts light on the current challenges, such as scalability, cost-effectiveness, and performance consistency, offering insightful perspectives for future research. This review underscores the transformative potential of BDC materials in MIHSCs and paves the way for next-generation energy storage technologies that are both high-performing and ecologically friendly. It calls for continued innovation and interdisciplinary collaboration to explore these sustainable materials, thereby contributing to advancing green energy technologies.