Preparation method of high-capacity linear supercapacitor electrode based on MXene/PANI

Abstract

The invention belongs to the field of flexible wearable energy storage equipment, and relates to a preparation method of a high-capacity linear supercapacitor electrode based on MXene / PANI. After thata MXene dispersion liquid is mixed with a hydrochloric acid solution of aniline in proportion, self-assembly is carried out at a low temperature to generate an MXene / PANI composite material, a smallamount of deionized water is added into the MXene / PANI composite material, ground into slurry, and coated on a glass plate to prepare a composite film, freeze drying is carried out, an adhesive tape is used to implement stripping, and a motor carries out twisting to prepare the film into a linear electrode. According to the linear supercapacitor, the MXene material and the PANI material can show extra pseudocapacitance in the acid electrolyte, and compared with an electrode structure which is too tight in wet spinning, the electrode has richer pores after mechanical twisting, and a higher active surface area is brought. In addition, the problems of high brittleness and poor mechanical properties after MXene film formation are solved.

Description

technical field [0001] The invention belongs to the field of flexible wearable energy storage devices, and in particular relates to a method for preparing a high-capacity linear supercapacitor electrode based on MXene / PANI. Background technique [0002] With the popularity of wearable electronic devices, the demand for traditional energy storage devices is also developing towards small size and light weight, such as fiber supercapacitors. As a traditional energy storage device, supercapacitors have the properties of fast charge and discharge capability, high power density and long life. As a flexible wearable device, it needs to have additional mechanical properties and the characteristics of being able to work normally in various outdoor environments under bending conditions. [0003] From the perspective of electrode materials, materials with good electrochemical performance while maintaining light weight, flexibility and wear resistance are the first choice for flexible ...

AI Technical Summary

Problems solved by technology

[0003] From the perspective of electrode materials, materials with good electrochemical performance while maintaining light weight, flexibility and wear resistance are the first choice for flexible wearable energy storage devices, such as two-dimensional transition metal carbide (MXene). As well as graphene-based materials, in previous studies, MXene was used as an electrode material for supercapacitors, mainly because of its good conductivity and the ability to exhibit additional pseudocapacitance in acidic electrolytes, but it can be used as a flexible electrode Said that its mechanical properties are poor, and the MXene film prepared by the conventional vacuum filtration method does not have good toughness, which limits its use as an electrode material for flexible devices.

Graphene-based materials have good flexibility, but the key to limiting their performance is that they cannot provide high capacity, which requires higher mass or larger area per unit capacitance, which is not in line with the lightweight need

Therefore, it is necessary to combine the advantages of the two. For example, CN 107680824 A constructed a MXene / rGO composite electrode. The patent pointed out that the flexibility of the composite material becomes better as the proportion of reduced graphene oxide is increased, but the capacity will be serious as the proportion of rGO increases. Decrease, the ratio of MXene:rGO decreased from 9:1 to 7:1 volume ratio capacitance decreased by 75% (600Fcm -3 to 200F cm -3 )

[0004] In order to solve the problem of low capacity, CN 109273273 A utilizes PANI, GO, PEDOT compound, in order to utilize PANI, the extra pseudocapacitance of PEDOT this kind of conductive elastomer material in acidic electrolyte improves the overall specific capacity, but from its CV (cycle It can be seen from the graph that the rate performance of the material is extremely poor, because at 5mV s -1 The material has completely lost its rectangular-like shape at a scan rate of 100, and does not show the redox reaction peak of the pseudocapacitive reaction.

[0005] Since MXene is brittle after film formation and has poor mechanical properties, the twisting process of the film may break the film, so wet spinning is used to prepare fiber electrodes such as CN 107680824 A, which can be seen from the scanning electron microscope image The internal structure of the wet-spun fiber electrode is very compact, which also reduces the specific surface area of ​​the electrode, increases the difficulty of ion diffusion inside the electrode, and limits its rate performance.

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