Preface

Thank you for choosing this book, which summarizes the latest research on supercapacitors. The concept of energy storage is necessary to provide a stable energy supply, and it will thus continue to develop in the future. Supercapacitors, as one of the many energy-storage technologies that have been developed so far, show the higher performance of electrode materials, electrolytes, and separators and demonstrate high energy density as well. In recent years, there has been noticeable progress in the development of hybrid capacitors with larger capacity compared to conventional electric double-layer-type capacitors. Supercapacitors are thus transforming from auxiliary power sources for lead-acid and lithium-ion batteries to next-generation power sources. Going forward, it is expected that the development of supercapacitors using ions, such as sodium and magnesium, and solid electrolytes will keep up the pace. I believe that it is important for researchers in this field to work together and combine technologies to create better products. I hope that this book will act as a platform for researchers to collaborate with each other, and I look forward to the success of the readers.

> **Daisuke Tashima** Department of Electrical Engineering, Faculty of Engineering, Fukuoka Institute of Technology (FIT), Fukuoka, Japan

#### **Aneeya Kumar Samantara**

Academy for Scientific and Innovative Research, CSIR-Institute of Minerals and Materials Technology (IMMT), Bhubaneswar, India

Section 1
