This book presents the select proceedings of 2nd Biennial International Symposium on “Fluids and Thermal Engineering” (FLUTE 2023). It covers the Scientific and Technological Advances in the field of materials and their devices for advanced energy storage and relevant energy conversion. Various topics covered in this book are sustainable energy conversion and storage technologies, renewable energy, water desalination, rechargeable batteries: metal–ion, metal–air, and redox flow batteries, emerging materials for energy storage, energy conversion devices, chemical energy storage, thermoelectric and thermos electrochemical cells, and many more. The book is useful for researchers and practitioners in the industry and academia.