Enhanced Tolerance to Stretch-Induced Performance Degradation of Stretchable MnO₂-Based Supercapacitors

Abstract

The performance of many stretchable electronics, such as energy storage devices and strain sensors, is highly limited by the structural breakdown arising from the stretch imposed. In this article, we focus on a detailed study on materials matching between functional materials and their conductive substrate, as well as enhancement of the tolerance to stretch-induced performance degradation of stretchable supercapacitors, which are essential for the design of a stretchable device. It is revealed that, being widely utilized as the electrode material of the stretchable supercapacitor, metal oxides such as MnO2 nanosheets have serious strain-induced performance degradation due to their rigid structure. In comparison, with conducting polymers like a polypyrrole (PPy) film as the electrochemically active material, the performance of stretchable supercapacitors can be well preserved under strain. Therefore, a smart design is to combine PPy with MnO2 nanosheets to achieve enhanced tolerance to strain-induced performance degradation of MnO2-based supercapacitors, which is realized by fabricating an electrode of PPy-penetrated MnO2 nanosheets. The composite electrodes exhibit a remarkable enhanced tolerance to strain-induced performance degradation with well-preserved performance over 93% under strain. The detailed morphology and electrochemical impedance variations are investigated for the mechanism analyses. Our work presents a systematic investigation on the selection and matching of electrode materials for stretchable supercapacitors to achieve high performance and great tolerance to strain, which may guide the selection of functional materials and their substrate materials for the next-generation of stretchable electronics.

Reconstruction of Mini‐Hollow Polyhedron Mn2O3 Derived from MOFs as a High‐Performance Lithium Anode Material

“…After the product is further charged to 3.0 V (Figure 4f), the lattice fringes of Mn 3 O 4 , Mn 2 O 3 , and MnO 2 are observed (with the d ‐spacings of lattice fringes for MnO x (1 < x ≤ 2) summarized in Table S4 in the Supporting Information). X‐ray photoelectron spectroscopy (XPS) in Figure S8 (Supporting Information) also confirm the different oxidation states of the products at 2.0 and 3.0 V 3, 4, 5, 46. This means that the oxidation peaks at around 1.25 V should be ascribed to the oxidation of metallic Mn to Mn 3 O 4 , and the peak around 2.5 V should be the incomplete oxidation of Mn 3 O 4 to Mn 2 O 3 and MnO 2 .…”

“…Manganese oxides materials have shown great potential application as energy materials, such as water oxidation and oxygen reduction,1, 2, 3 electrochemical capacitors,4, 5 lithium–O 2 batteries,6 and lithium‐ion batteries (LIBs) 7, 8, 9, 10, 11, 12, 13, 14, 15. Owing to their high specific theoretical capacity, low cost, and environmentally benign nature, manganese oxides (MnO x , 1 ≤ x ≤ 2) are believed to be the most promising alternative anode materials for next generation LIBs 11, 13, 16, 17.…”

Metal carbonates: alternative to metal oxides for supercapacitor applications? A case study of MnCO3 vs MnO2

“…where I is the discharge (or charge) current, t is the discharge Table 1, MnCO 3 is cheaper and safer than MnO 2 [25]. These attributes place MnCO 3 above MnO 2 and hence could be a potential alternative to MnO 2 .…”

A skin-like stretchable colorimetric temperature sensor

“…Different from them, the main advantages of stretchable systems are associated with their low modulus, light weight, and large deformability without performance failure, and thus enabling close skin contact and conformal lamination onto complex nonplanar surfaces [6,7]. To date, various flexible or stretchable devices have been used in the field of flexible display, and wearable technologies such as health monitoring and soft robotics [8][9][10][11][12][13]. For instance, high-adhesion stretchable electrodes have been used both for stretchable electrodes and strain sensors to reliably detect electromyography signals and the joint motions [14].…”