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The chitosan-induced self-assembly strategy is developed to construct MXene into a flexible 3D Ti 3 C 2 T x @Chitosan film. The film with 3D ordered and porous structure shows excellent rate capability and low mass-loading dependence. The hydrophilic crosslinked chitosan, which are interconnected and interwoven with MXene nanosheets, also endows the film with enhanced mechanical strength and flexibility. [Display omitted] • 3D Ti 3 C 2 T x @Chitosan film was prepared via a chitosan-induced self-assembly strategy. • The 3D ordered and porous electrode exhibited enhanced electrochemical performance. • The mechanical properties for the MXene-based composite film are significantly enhanced. • The assembled symmetric supercapacitor delivers ultra-high power density and flexibility. MXenes with outstanding electric conductivity and surface chemistry are promising materials for future energy storage. However, processing MXenes into free-standing films can lead to restacking and aggregation of the 2D nanosheets, which limits the ionic kinetics within materials. Current solutions are difficult for films to satisfy both rate performance and flexibility. Herein, we propose a novel chitosan-induced self-assembly strategy to construct MXene into flexible Ti 3 C 2 T x @Chitosan films with 3D ordered and porous structure. The interconnected 3D network provides fast transport channels for electrons and electrolyte ions. Therefore, the film exhibits excellent rate capability and low mass-loading dependence. The Ti 3 C 2 T x @Chitosan film with a high mass loading of 4 mg−2 delivers a capacitance of 245.2F g−1 at 2 V s−1, which demonstrates 57.1% capacitance retention with 400-fold scan rate increase. The crosslinked chitosan is interconnected and interwoven with MXene nanosheets, resulting in enhanced mechanical strength and flexibility for Ti 3 C 2 T x @Chitosan. Furthermore, by applying Ti 3 C 2 T x @Chitosan film to assemble flexible symmetrical supercapacitors, an ultra-high power density of 143.2 μWh cm−2 can be attained. This work develops a simple route for assembling 2D MXene into 3D high-flexible porous films as state-of-the-art electrodes for high-rate pseudocapacitive energy storage. [ABSTRACT FROM AUTHOR]

Interface engineering has been employed on commercial Bi 0.5 Sb 1.5 Te 3 (BST) to obtain synergistically enhanced thermoelectric performance via incorporating amorphous Sb 2 S 3 nano spheres. [Display omitted] • Conducting interface engineering via incorporating Sb 2 S 3 in Bi 0.5 Sb 1.5 Te 3. • Decoupling thermal and electrical properties via introducing Sb/BST interfaces. • Obtaining a high zT of ∼ 1.31 at 330 K in Bi 0.5 Sb 1.5 Te 3 -0.4%Sb 2 S 3. Tremendous efforts have been focusing on the improvement of p-type (Bi, Sb) 2 Te 3 -based thermoelectric materials for commercial applications. In this study, we achieve versatile interface engineering through a surface decoration of Bi 0.5 Sb 1.5 Te 3 by amorphous Sb 2 S 3 combining with spark plasma sintering, which introduces semi-coherent Sb/Bi 0.5 Sb 1.5 Te 3 interfaces and dopes S into Bi 0.5 Sb 1.5 Te 3. Semi-coherent Sb/Bi 0.5 Sb 1.5 Te 3 interfaces strongly scatter phonons and lower energy carriers, leading to decreased thermal conductivity and increased Seebeck coefficient, while the electrical conductivity is not sacrificed due to the compromise of the slightly reduced carrier mobility by interfacial scattering and the increased carrier concentration by S doping. Benefited from the decoupled thermoelectric properties, a significantly enhanced power factor of 3345.40 μW m−1 K−2 and a low thermal conductivity of 0.78 W m−1 K−1 is obtained in Bi 0.5 Sb 1.5 Te 3 -0.4%Sb 2 S 3 , leading to a high peak zT of ∼ 1.31 at 330 K, which shows a 54% enhancement compared with pristine Bi 0.5 Sb 1.5 Te 3. Moreover, a conversion efficiency of ∼ 7.6% can be predicted in a single leg Bi 0.5 Sb 1.5 Te 3 -0.4%Sb 2 S 3 -based module under a cold side temperature of 300 K and hot side temperature of 480 K. This study paves a facile amorphous Sb 2 S 3 induced interface engineering strategy for the development of high performance (Bi,Sb) 2 Te 3 -based thermoelectric materials. [ABSTRACT FROM AUTHOR]