Developing highly robust and efficient electrode materials is of critical importance to promoting the energy density of current supercapacitors for commercialization. Herein, we report an efficient catalyst with monodispersed Mn single-atoms embedded in carbon nanotubes (Mn-CNTs) for enhancing the electrode performance of supercapacitors. A high specific capacitance (1523.6 F·g⁻¹ at 1.0 A·g⁻¹) can be achieved, which is about twice as high as the specific capacitance of the electrode material without the introduction of Mn single-atoms. Remarkably, the asymmetric electrochemical capacitor created with Mn-CNT and activated carbon exhibits a high energy density of 180.8 Wh·kg⁻¹ at a power density of 1.4 kW·kg⁻¹, much higher than most reported results. The study shows that the integration of Mn atoms into the CNT can enhance the charge transport capacity and the number of polar active sites of Mn-CNT and then facilitate chemical interactions between Mn-CNT and OH⁻. This work provides a novel strategy to enable high-energy storage in supercapacitors by introducing single-atoms into carbon nanotubes to improve electrodes’ energy density and cycle life.

The rapid development of wearable electronic products brings challenges to corresponding power supplies. In this work, a thermally stable and stretchable ionogel-based triboelectric nanogenerator (SI-TENG) for biomechanical energy collection is proposed. The ionic conductivity of the ionogel increased to 0.53 S·m⁻¹ through optimal regulation of the amount of amino-terminated hyperbranched polyamide (NH₂-HBP), which also has high strain of 812%, excellent stretch recovery, and wide operating temperature range of −80 to 250 °C. The SI-TENG with this ionogel as electrode and silicone rubber both as the triboelectric layer and encapsulation layer exhibits high temperature stability, stretchability, and washability. By adding appropriate amount of nano SiO₂ to triboelectric layer, the output performance is further improved by 93%. Operating in single-electrode mode at 1.5 Hz, the outputs of a SI-TENG with an area of 3 cm × 3 cm are 247 V, 11.7 μA, 78 nC, and 3.2 W·m⁻², respectively. It was used as a self-charging power supply to charge a 22 μF capacitor to 1.6 V in 167 s with the palm patting and then to power the electronic calculator. Furthermore, the SI-TENG can also be used as a self-powered motion sensor to detect the amplitude and frequency of finger bending, human swallowing, nodding, and shaking of the head motion changes through the analysis of the output voltage.

A flexible and stable power supply is essential to the rapid development of wearable electronic devices. In this work, a transparent, flexible, temperature-stable and ionogel electrode-based self-healing triboelectric nanogenerator (IS-TENG) was developed. The ionogel with excellent stretchability (1,012%), high ionic conductivity (0.3 S·m⁻¹) and high-temperature stability (temperature range of −77 to 250 °C) was used as the electrode of the IS-TENG. The IS-TENG exhibited excellent transparency (92.1%) and stability. The output performance did not decrease when placed in a 60 °C oven for 48 h. In addition, the IS-TENG behaved like a stable output in the range of −20 to 60 °C. More importantly, the IS-TENG could also achieve self-healing of electrical performance at temperatures between −20 and 60 °C and its output can be restored to its original state after healing. When the single-electrode IS-TENG with an area of 3 cm × 3 cm was conducted under the working frequency of 1.5 Hz, the output values for open-circuit voltage, short-circuit current, short-circuit transferred charge, and maximum peak power density were 189 V, 6.2 μA, 57 nC, and 2.17 W·m⁻², respectively. The IS-TENG enables to harvest biomechanical energy, and drive electronic devices. Furthermore, the application of IS-TENGs as self-driven sensors for detecting human behavior was also demonstrated, showing good application prospects in the field of wearable power technology and self-driven sensing.

The urgent demand for portable electronics has promoted the development of high-efficiency, sustainable, and even stretchable self-charging power sources. In this work, we propose a flexible self-charging power unit based on folded carbon (FC) paper for harvesting mechanical energy from human motion and power portable electronics. The present unit mainly consists of a triboelectric nanogenerator (FC-TENG) and a supercapacitor (FC-SC), both based on folded carbon paper, as energy harvester and storage device, respectively. This favorable geometric design provides the high Young's modulus carbon paper with excellent stretchability and enables the power unit to work even under severe deformations, such as bending, twisting, and rolling. In addition, the tensile strain can be maximized by tuning the folding angle of the triangle-folded carbon paper. Moreover, the waterproof property of the packaged device make it washable, protect it from human sweat, and enable it to work in harsh environments. Finally, the as-prepared self-charging power unit was tested by placing it on the human body to harvest mechanical energy from hand tapping, foot treading, and arm touching, successfully powering an electronic watch. This work demonstrates the impressive potential of stretchable self-charging power units, which will further promote the development of high Young's modulus materials for wearable/portable electronics.