Search

MXene based layered materials have exhibited excellent performance in supercapacitor applications owing to their high conductivity. However, device planarization hinders their broader ability in a film-based energy storage device. Here, we have demonstrated the fabrication of self-assembled MXene–graphene oxide (M-GO) composites based on the electrostatic interaction between MXene and GO solutions. The as-prepared M-GO composite possessed homogeneous structures and tunable conductivities according to different GO contents, which benefit both charge storage and ions transmission. The first-assembly sandwiched supercapacitors based on these M-GO composites showed a maximum specific capacitance value of 39.0 mF/cm2 (10.9 mF/cm2 for MXene based devices). The enhanced electrochemical performance after self-assembly was due to the improved interface effect between electrodes and electrolytes. Additionally, the introduction of GO guarantees the completeness of designed M-GO patterns without the need for additives, and it is worth noting that with the assistance of a laser fabrication technique, planar supercapacitors based on the most suitable M-GO (with mass ratio of M:GO = 1:1) composite could be obtained by ablating the unwanted areas. Additionally, planar M-GO based supercapacitors also exhibited excellent electrochemical performance, which demonstrated the great potential of M-GO composite supercapacitors in wearable electronic applications. [ABSTRACT FROM AUTHOR]

Here, we have proposed a new scheme to enhance the electrochemical performance of LIG-based supercapacitors by combining the advantages of pseudocapacitive MnO 2 nanoparticles, easy-removed GO precursors, and programmable processing of LIG. The formation of GO-MnO 2 precursor with proper GO content not only preserves the abundant active sites of MnO 2 nanoparticles, but also ensures better ion transportation properties by adjusting the distribution of easy-stacking MnO 2 nanoparticles. Therefore, the as-prepared LIG-GO-MnO 2 films possess more active sites, better and more plentiful microstructures, and lower sheet resistance than solo LIG films, and the resultant LIG-GO-MnO 2 -based supercapacitors exhibit enhanced electrochemical performance compared with LIG based supercapacitors. Moreover, the LIG-GO-MnO 2 -based supercapacitors also display good cycling stability, with at least 92.59 % specific capacitance retention after 1000 cycling tests. And after more than nine months later, the LIG-GO-MnO 2 based-supercapacitor still shows a specific capacitance retention of ∼100 %. What's more, the need for additive connections. In-series LIG-GO-MnO 2 -based supercapacitors could be obtained by a single laser induced process owing to the performance uniformity of a single supercapacitor, which realize the voltage extension from 0.8 to 2. 4 V and power an LED. In this work, we have demonstrated the possibility of using GO as an auxiliary agent instead of routine roles as active materials and we hope this proposal will help expand the diversity of easy-removed nano-composite precursors in developing LIG-based devices in practical applications. [ABSTRACT FROM AUTHOR]

The construction of the easy-removed self-assembled MXene-GO composites has been proposed to enhance the application diversity of LIG based material in energy storage areas. The as-prepared composite combines the advantages of both high conductivity and abundant active sites of MXene, and porous microstructure of LIG, which presents modified interface characteristics and improved electrochemical performance. Additionally, laser induction technique used here to realize the graphenization of PI, introduction of pseudocapacitive MXene, and patterning and integration of series LIG-C based supercapacitors. [Display omitted] • Easy-removed self-assembled MXene-graphene oxide composite to promote the capacitive performance of LIG-based supercapacitors. • The composites (LIG-C) combine high conductivity of MXene particles and good microstructures of LIG. • LIG-C possesses low sheet resistance of 15.0 Ω sq−1 and good stability including a specific capacitance retention of 98.9% after six months and 102.4% after 1000 cycles charge–discharge process. • LIG-C based supercapacitor possesses good performance uniformity and conformal ability, which will be suitable for the development of conformal electronic devices. Since pure laser-induced graphene (LIG)-based supercapacitors suffer poor capacity, additional active materials need to be introduced to promote the capacitive performance of LIG-based electrodes. However, the effective introduction and the removal of redundant active materials remain challenging during the fabrication of planar LIG-based supercapacitors. Here we propose the easy-removed self-assembled MXene-graphene oxide composite (C) for the preparation of LIG-based supercapacitors. Owing to the combination of homogeneous C solution and programmable laser-induced process, the as-prepared supercapacitor based on laser-induced C covered polyimide (PI) films (LIG-C) showed enhanced capacity and improved ion transportation characteristics due to the low sheet resistance (15.0 Ω sq−1) and homogenous microstructures. What's more, the LIG-C-based supercapacitor prepared under laser power of 3 W exhibited good stability including a specific capacitance retention of 98.9% after six months and 102.4% after 1000 cycles charge–discharge process. Additionally, LIG-C-based supercapacitors also showed good performance uniformity, and series LIG-C-based supercapacitors could power a LED because of a voltage expansion. At the same time, LIG-C-based supercapacitors possessed good deformation-resisting properties under different bending states, which showed promising potential for future conformal electronics device applications. And we hope that this work will pave a new way for LIG-based material in the energy storage field. [ABSTRACT FROM AUTHOR]