Application of Mxene materials in flexible energy storage and devices

With the increasing demand for wearable electronic products, flexible energy storage devices have been rapidly developed. MXenes is considered as a promising flexible electrode due to its ultra-high volumetric capacity, metal conductivity, superior hydrophilicity and rich surface chemistry. Pure MXene, MXene carbon composites, MXene metal oxide composites and MXene polymer composites have applications in flexible electronic devices such as sensors, nanogenerators and electromagnetic interference shielding. In addition, the application of MXenes materials in flexible devices affects the stress, strain, conductivity, capacitance and other properties are compared to help researchers maintain a balance between mechanical and electrochemical properties when designing flexible devices.

01 Flexible supercapacitor

Flexible supercapacitors (SCs) are expected to achieve higher energy density per unit volume compared to traditional carbon-based materials batteries. First, the MXene material exhibits an extremely high volumetric energy density due to its high energy density and large Faraday pseudocapacitance (derived from rich surface chemistry), in addition, MXene can also act as a fluid collector due to metal conductivity. A flexible electrode composed of a fluid collector and an active material is then expected to be built entirely on a flat mxene sheet to further increase the bulk energy density of the flexible SCs to power wear-resistant electrons. For flexible MXene-based composites, composites mainly consisting of mxene and carbon nanomaterials, mainly including reduced graphene oxide (rGO) and carbon nanotubes (CNT), etc., to prepare flexible thin film electrodes. This strategy effectively prevents the reaccumulation of MXene sheets and significantly improves the flexibility. Polymers are another promising additive that can be combined with mxenes to greatly improve the mechanical properties of materials, especially conductive polymers, which can optimize mechanical strength without sacrificing electrical conductivity. In addition, metal oxides with high Faraday pseudocapacitance can also be used to bond with MXene for higher electrochemical properties. These nanocomposite methods facilitate the preparation of flexible MXene-based SCs, which have excellent flexibility, high specific capacity, and excellent mechanical properties to power wearable electronics.