Facile Synthesis of MnO₂/Ti₃C₂T_x/CC as Positive Electrode of All‐Solid‐State Flexible Asymmetric Supercapacitor

Abstract

The pseudo‐capacitance material Manganese dioxide (MnO2) is widely used as electrode materials for supercapacitors; however, its poor electrical conductivity hinders the realization of high specific capacitance. Herein, the MnO2 and Ti3C2Tx (MXene) were deposited on carbon cloth (CC) by a facile two‐step electrodeposition method for synthesizing free‐binder MnO2/Ti3C2Tx/CC composite electrode. Benefiting from the excellent conductivity of Ti3C2Tx and the excellent pseudo‐capacitance performance of MnO2, the as‐obtained composite electrode exhibited a higher specific capacitance (411.5 F g−1 at the current density of 1 A g−1). In addition, all‐solid‐state flexible asymmetric supercapacitors were successfully assembled from the positive electrode of MnO2/Ti3C2Tx/CC and the negative electrode of Ti3C2Tx/CC. The as‐assembled supercapacitor presented a large operating voltage of 1.7 V, a high energy density of 24.3 Wh Kg−1 at a power density of 850 W Kg−1. This work provides a simple and efficient approach to prepare composite electrodes and fabricate all‐solid‐state asymmetric supercapacitors with high electrochemical performances.

Hierarchical V4C3TX@NiO-reduced graphene oxide heterostructure hydrogels and defective reduced graphene oxide hydrogels as free-standing anodes and cathodes for high-performance asymmetric supercapacitors

“…In fact, the specific capacitance of the V 4 C 3 T X @NiO-RGO electrode was superior to those of Ti 3 C 2 T X -based electrodes reported previously, as displayed in Table S1 (ESI †). [44][45][46][47][48][49][50][51][52][53][54][55][56] The remarkable rate capability of V 4 C 3 T X @NiO-RGO is attributed to the synergistic coupling effect among the structural components and the 3D architecture. Specifically, the conductive V 4 C 3 T X core in the heterostructure offers both abundant transport channels for ions and active interfacial centers, while the ultrathin NiO shells can increase the pseudocapacitance and promote the diffusion and migration of electrolyte ions.…”

“…9g). 48,52,55,[71][72][73][74][75][76] Consecutive GCD measurements at a current density of 10 A g À1 for 10 000 cycles were then carried out to evaluate the cycling stability. From Fig.…”

A high-performance supercapacitor based on free-standing V4C3TX@NiO-reduced graphene oxide core–shell hierarchical heterostructured hydrogel electrodes

“…The specific capacitance of the V 4 C 3 T X @NiO-RGO electrode was superior to those of Ti 3 C 2 T X -based electrodes reported previously, as displayed in Table 1. 44–56 The excellent rate capability of V 4 C 3 T X @NiO-RGO is attributed to the synergistic coupling effect among the structural components and the 3D interconnected architecture. Specifically, the highly conductive V 4 C 3 T X core in the heterostructure offers both abundant transport channels for ions and active interfacial centers, while the ultrathin NiO shells can effectively increase the capacitance.…”

“…6d). [45][46][47][50][51][52][53][54] Long-term cycle stability is another signicant factor in practical applications, which was evaluated through a consecutive charge-discharge process at a current density of 10 A g −1 for up to 10 000 cycles (Fig. 6e).…”

A Flexible Asymmetric NaFePO4/Carbon Cloth Supercapacitor Using Crosslinked Polyacrylate Gel as Electrolyte

“…Considering the mass loading of NaFePO 4 on CC (0.3 mg ⋅ cm −2 ), the mass specific capacitance of NaFePO 4 /CC//NaPA//AC/CC is 154.43 F ⋅ g −1 at the current density is 3.3 A ⋅ g −1 . This specific capacitance is superior to the reported CoFe 2 O 4 /CFC//PSS//Fe 2 O 3 ‐CNTs/CFC (181.30 F ⋅ g −1 at 1 A ⋅ g −1 ), [31] MnO 2 /CC//AC/CC (133.02 F ⋅ g −1 at 3 A ⋅ g −1 ), [32] Ni 0.85 Se/CFC//KOH/PVA//AC/CFC (81 F ⋅ g −1 at 1 A ⋅ g −1 ), [33] and MnO 2 /Ti 3 C 2 T x /CC//PVA‐LiCl//Ti 3 C 2 T x /CC (60.60 F ⋅ g −1 at 1 A ⋅ g −1 ) [34] . With the specific capacitance of 154.43 F ⋅ g −1 , the energy density of NaFePO 4 /CC//NaPA//AC/CC can be 5.36 Wh ⋅ kg −1 , and the power density reaches 839.31 W ⋅ kg −1 .…”