Pillared Structure Design of MXene with Ultralarge Interlayer Spacing for High-Performance Lithium-Ion Capacitors

Abstract

Two-dimensional transition-metal carbide materials (termed MXene) have attracted huge attention in the field of electrochemical energy storage due to their excellent electrical conductivity, high volumetric capacity, etc. Herein, with inspiration from the interesting structure of pillared interlayered clays, we attempt to fabricate pillared TiC MXene (CTAB-Sn(IV)@TiC) via a facile liquid-phase cetyltrimethylammonium bromide (CTAB) prepillaring and Sn pillaring method. The interlayer spacing of TiC MXene can be controlled according to the size of the intercalated prepillaring agent (cationic surfactant) and can reach 2.708 nm with 177% increase compared with the original spacing of 0.977 nm, which is currently the maximum value according to our knowledge. Because of the pillar effect, the assembled LIC exhibits a superior energy density of 239.50 Wh kg based on the weight of CTAB-Sn(IV)@TiC even under higher power density of 10.8 kW kg. When CTAB-Sn(IV)@TiC anode couples with commercial AC cathode, LIC reveals higher energy density and power density compared with conventional MXene materials.

MXene‐Based Composites: Synthesis and Applications in Rechargeable Batteries and Supercapacitors

“…In addition to metals, carbon-based materials, metal oxides, metal sulfides, and polymers, many other materials have been used to compound with MXene, such as metal-organic frameworks, [223] metal organics, [224,225] metal hydrides, [226,227] sulfur, [228] glass fibers, [229] graphene-like carbon nitride (g-C 3 N 4 ), [230] etc.…”

“…Moreover, the hydrophilic or oxygen-terminated groups are firmly attached to the surface of the composite giving it a contact angle of 14.1°, which is an advantageous reserve of transformational energy in inorganic electrolyte. [228] In summary, in addition to metals, carbon-based materials, metal oxides, metal sulfides, and polymers, many other materials have been used to compound with MXene, such as metal-organic frameworks, [223] metal organics, [224,225] metal hydrides, [226,227] sulfur, [228] glass fibers, [229] graphene-like carbon nitride (g-C 3 N 4 ), [230] etc., in rechargeable batteries system and have shown remarkable electrical performance. [232] Both MgH 2 and NaAlH 4 have a reversible hydrogen storage property, so Liu et al and Wu et al combined Ti 3 C 2 T x with these metal hydrides by ball milling to obtain a composite material with excellent hydrogen storage properties.…”

“…[ PVP-Sn(IV)/Ti 3 C 2 T x Electrostatic interaction and ion exchange with π-π coordination 513 mA h g −1 (94.3%) at 500 mA g −1 after 200 cycles [225] CTAB-Sn(IV)/Ti 3 C 2 T x 506 mA h g −1 (96.9%) at 1000 mA g −1 after 250 cycles [224] Ti 3 C 2 T x /rGO Solution mixing, hydrazine reduction, and annealing 212 mA h g −1 1000 mA g −1 after 1000 cycles [244] Ti 3 C 2 T x /CNTs Solution mixing 428 mA h g −1 at 160 mA g −1 after 300 cycles [70] V2C Solution mixing 252 mA h g −1 at 500 mA g −1 after 500 cycles [170] p-Ti 3 C 2 T x /CNTs Solution mixing 500 mA h g −1 at 160 mA g −1 after 100 cycles [148] Ti 3 C 2 T x /CNF High-temperature catalytic 97 mA h g −1 (100%) at 32 A g −1 after 2900 cycles [71] www.advmatinterfaces.de has been reported that many MXenes are used as electrode materials. However, the high cost of lithium resources and low energy density limits their application in EVs and HEVs for the future.…”

“…This unique structure gives Ti 3 C 2 T x /CNF composite large surface areas, which offer many active sites of the Li + ions on the surface of Ti 3 C 2 T x flakes. [224,225,252] Comparing the Ti 3 C 2 T x /SnO 2 /HfO 2 composite with PVP-Sn(IV)/Ti 3 C 2 T x composite and CTAB-Sn-(IV)/Ti 3 C 2 composite, the tin ion-containing composites show lower electrochemical performance. Therefore, such composites reveal excellent electrochemical performance in LIBs (97 mA h g −1 at 32 A/h after 2900 cycles).…”

“…Furthermore, with a large number of points of a junction on the surface of Ti 3 C 2 T x flakes, the CNFs can develop with the far points of the Ti 3 C 2 T x surface, and form a 3D conductive net. [224,225,252] The CTAB-Sn(IV)/ Ti 3 C 2 T x composite shows better electrochemical performances that the PVP-Sn(IV)/Ti 3 C 2 T x composite since the CTAB serves as an excellent support between the Ti 3 C 2 T x layers. [71] To further enhance the electronic and ion conductivity of MXenes-based composites, it is feasible to combine with some specific materials with excellent electronic and ion conductivity property, such as Ag nanoparticles, [216] and CNTs, [70,151,235,251] and so on.…”