Recent progress of unconventional and multifunctional integrated supercapacitors

Integration can diversify the function of a device with the same volume, therefore it facilitates the development of portable, wearable and flexible electronics. In this review, we described several kinds of novel and unconventional multifunctional integrated supercapacitors which can not only be used to storage energy but also be applied to other fields such as photodetecting, electrochromics, monitoring physiological/mechanical activities, gas sensor, and so on. First, a brief introduction of the significance and advantages of multifunctional integrated supercapacitors was presented. Then we outlined the enormous progress which has been made in the area of multifunctional integrated supercapacitors. In the end, the prospects and further developments in this exciting field were also suggested.

Integrated solar capacitors for energy conversion and storage

Solar energy is one of the most popular clean energy sources and is a promising alternative to fulfill the increasing energy demands of modem society. Solar cells have long been under intensive research attention for harvesting energy from sunlight with a high power-conversion efficiency and low cost. However, the power outputs of photovoltaic devices suffer from fluctuations due to the intermittent instinct of the solar radiation. Integrating solar cells and energy- storage devices as self-powering systems may solve this problem through the simultaneous storage of the electricity and manipulation of the energy output. This review the research progress in the integration of new-generation solar cells with supercapacitors, with emphasis on the structures, materials, performance, and new design features. The current challenges and future prospects are discussed with the aim of expanding research and development in this field.

Flexible supercapacitors based on carbon nanotubes

Since carbon nanotubes（CNTs） possess unique one dimensional（1D） structure, considerable attention has been paid to constructing CNTs into macroscopic materials with different dimensions, including 1D fibers,2D films, and 3D foams. Such macroscopic CNT materials exhibit high conductivity, large surface area, as well as good mechanical properties, and thus can be directly used as the flexible supercapacitor（SC） electrodes or the scaffolds for supporting pseudo-capacitive electrode materials. Based on these macroscopic CNT electrodes, diverse SCs with different structures, including flexible, stretchable and/or compressible fiber and thin film SCs, have been designed. This review provides an overview of recent progress towards the development of flexible SCs based on macroscopic CNTs-based electrodes, with a focus on electrode preparation and configuration design as well as their integration with other multifunctional devices.Future development and prospects in the CNTs-based flexible SCs are also discussed.