All‐Printed MnHCF‐MnO_x‐Based High‐Performance Flexible Supercapacitors

Abstract

Here, a simple active materials synthesis method is presented that boosts electrode performance and utilizes a facile screen‐printing technique to prepare scalable patterned flexible supercapacitors based on manganese hexacyanoferrate‐manganese oxide and electrochemically reduced graphene oxide electrode materials (MnHCF‐MnOx/ErGO). A very simple in situ self‐reaction method is developed to introduce MnOx pseudocapacitor material into the MnHCF system by using NH4F. This MnHCF‐MnOx electrode materials can deliver excellent capacitance of 467 F g−1 at a current density of 1 A g−1, which is a 2.4 times capacitance increase compared to MnHCF. In addition a printed, patterned, flexible MnHCF‐MnOx/ErGO supercapacitor is fabricated, showing a remarkable areal capacitance of 16.8 mF cm−2 and considerable energy and power density of 0.5 mWh cm−2 and 0.0023 mW cm−2, respectively. Furthermore, the printed patterned flexible supercapacitors also exhibit exceptional flexibility, and the capacitance remains stable, even while bending to various angles (60°, 90°, and 180°) and for 100 cycles. The flexible supercapacitor arrays integrated by multiple prepared single supercapacitors can power various LEDs even in the bent states. This approach offers promising opportunities for the development of printable energy storage materials and devices with high energy density, large scalability, and excellent flexibility.

3D Wearable Fabric‐Based Micro‐Supercapacitors with Ultra‐High Areal Capacitance

“…The areal energy and power density values of the fabric-based MSCs are also compared with previously reported devices. [12,15,[20][21][22][32][33][34] As shown in Figure 3h, the fabric-based MSCs exhibit a highest areal energy density of 12.03 µW h cm −2 at a power density of 32 mW cm −2 , which exceeds the reported values. This indicates the 3D fabricbased MSCs are superior in areal performance due to the unique structural advantages, and thus demonstrate great potential to be used in future miniaturized and wearable electronics.…”

Biaxial Stretchability in High‐Performance, All‐Solid‐State Supercapacitor with a Double‐Layer Anode and a Faradic Cathode Based on Graphitic‐2200 Knitted Carbon Fiber

“…The accessible literature regarding the flexibility of SCs are far from sufficient, and the scope of the research field still requires innovation. However, the studies on the bendability/rollability/twistability of electrode materials are expanding satisfactorily, [ 6,7 ] and the stretchability of entire SC device (electrode materials, electrolyte, and separator) is thought‐provoking. [ 8 ] Uniaxial stretching on supercapacitor devices is currently being reported on, [ 9 ] but the existing reports on the fabrication of biaxially ( xy ) stretchable supercapacitors are far from meeting the requirements of next‐generation flexible electronics.…”

3D Printed Electrochromic Supercapacitors with Ultrahigh Mechanical Strength and Energy Density

“…To further evaluate the practical potential of the fabricated multifunctional SSC, the energy and power densities were calculated based on the bottom area and total volume of the whole device and plotted in Figure 5e and Figure S4 (Supporting Information), respectively. Although the voltage window used for testing is only 0.6 V, the device displays a high areal energy density of 0.60 mWh cm −2 while the maximal power density is still as high as 129 mW cm −2 , which are much higher than those of previous reported other similar symmetric SCs such as the screen printed MnHCF-MnO x /ErGO SC (0.5 mWh cm −2 at 0.0023 mW cm −2 ), [43] fused deposition modeled AC SC fiber (0.031 mWh cm −2 at 3.9 mW cm −2 ), [44] 3D-printed MXene-AgNW-MnONW-C60 SC (0.019 mWh cm −2 at 58.3 mW cm −2 ), [45] MoO x SC (0.016 mWh cm −2 at 2.53 mW cm −2 ), [46] PEDOT:PSS SC (1.63 μWh cm −2 at 0.4 mW cm −2 ), [47] screen printed PG/WJMgraphene:SWCNTs SC (0.36 μWh cm −2 at 1.13 mW cm −2 ), [48] and even asymmetric supercapacitors (ASCs) with wider potential window such as the TCC//LC-WO 3 /TCC ASC (0.66 mWh cm −2 at 1.7 mW cm −2 ), [39] P-Mn 3 O 4 /C//AC ASC (0.573 mWh cm −2 at 1.7 mW cm −2 ), [36] CWS/Ni//graphene ASC (0.102 mWh cm −2 at 0.675 mW cm −2 ), [42] 3D-printed V 2 O 5 //G-VNQDs micro ASC (0.08 mWh cm −2 at 3.77 mW cm −2 ), [49] WO 3 /G/PT//G/ PT ASC (0.06 mWh cm −2 at 2.32 mW cm −2 ), [50] screen printed kelp-carbon//Zn hybrid micro capacitor (0.0082 mWh cm −2 at 0.04 mW cm −2 ). [51] Besides, as a key parameter for the practical application of SCs, the cycling performance of the device was further investigated.…”