Recent advances in flexible/stretchable batteries and integrated devices

In recent years, flexible/stretchable batteries have gained considerable attention as advanced power sources for the rapidly developing wearable devices. In this article, we present a critical and timely review on recent advances in the development of flexible/stretchable batteries and the associated integrated devices. We first provide an overview on the requirements for flexible or stretchable batteries. This is followed by the design and development strategies for free-standing flexible/stretchable electrodes. We then summarize the recent developments of flexible/stretchable electrolytes and separators as the key battery components as well as various flexible/stretchable batteries and their integrated devices. Finally, the current challenges and future perspectives in this emerging field of flexible/stretchable batteries are also discussed.