Search

• V 2 O 5 · n H 2 O/rGO was synthesized via a dual electrostatic assembly strategy. • The synergistic contribution in the composite improves the energy storage ability. • The composite exhibits excellent rate capability when used as cathode for LIBs. As well-known, hydrated vanadium pentoxide (V 2 O 5 · n H 2 O) has a larger layer spacing than orthogonal V 2 O 5 , which could offer more active sites to accommodate lithium ions, ensuring a high specific capacity. However, the exploration of V 2 O 5 · n H 2 O cathode is limited by its inherently low conductivity and slow electrochemical kinetics, leading to a significant decrease in capability. Herein, we prepared V 2 O 5 · n H 2 O/reduced graphene oxide (rGO) composite with low rGO content (8 wt%) via a simple yet effective dual electrostatic assembly strategy. When used as the cathode material for lithium-ion batteries (LIBs), V 2 O 5 · n H 2 O/rGO manifests a high reversible capacity of 268 mAh g−1 at 100 mA g−1 and especially an excellent rate capability (196 mAh g−1 at 1000 mA g−1 and 129 mA h g−1 at 2000 mA g−1), surpassing those of the V 2 O 5 /carbon composites reported in the literatures. Notably, the remarkable performance should be referable to the synergetic effects between one-dimensional V 2 O 5 · n H 2 O nanobelts and two-dimensional rGO nanosheets, which provide a short transport pathway and enhanced electrical conductivity. This strategy opens a new opportunity for designing high-performance cathode material with excellent rate performance for advanced LIBs. [ABSTRACT FROM AUTHOR]

[Display omitted] Transition metal phosphides, especially bimetallic phosphides, are promising noble-metal-free electrocatalysts for hydrogen evolution reaction (HER). However, their inferior charge transfer ability constrains further performance improvement. In this work, a facile strategy is reported to fabricate Co 2 P/Ni 2 P/carbon nanotube (CNT) composite from a precursor Co-Ni Prussian blue analogue. The combination of Co 2 P/Ni 2 P and CNT endows Co 2 P/Ni 2 P/CNT with improved electrical conductivity and a richer electrochemically active surface area. As a result, the Co 2 P/Ni 2 P/CNT composite exhibits desirable HER activities across a wide pH range, delivering a benchmark current density of 10 mA cm−2 at overpotentials as low as 151 and 202 mV in 0.5 M H 2 SO 4 and 1 M KOH electrolytes, respectively, as well as remarkable electrocatalytic stabilities over 48 h in both electrolytes. This strategy enables the design of high-performance electrocatalysts for efficient and stable hydrogen generation. [ABSTRACT FROM AUTHOR]

Abstract: Carbon nanotubes (CNTs) films have been successfully fabricated by electrophoretic deposition (EPD) technique and used as counter electrodes of dye-sensitized solar cells (DSSCs). The CNTs counter electrodes consisting of a large number of bamboo-like structures with defect-rich edge planes exhibit a highly interconnected network structure with high electrical conductivity and good catalytic activity. A high photovoltaic conversion efficiency of 7.03% is achieved for DSSCs based on the CNTs counter electrodes, which is comparable to the cell based on conventional Pt counter electrode at one sun (AM 1.5G, 100mWcm−2). The results suggest that the present synthetic strategy provides a potential feasibility for the fabrication of low-cost flexible counter electrodes of DSSCs using a facile deposition technique from an environmentally “friendly” solution at low temperature. [Copyright &y& Elsevier]

[Display omitted] Aqueous zinc-ion batteries (ZIBs) have been considered to be potential energy storage devices because of their cost-effectiveness and environmental friendliness. However, most of the cathode materials reported in ZIBs exhibit poor electrochemical performances like capacity fading during cycling and inferior performance at high current densities, which significantly hinder the further development of ZIBs. Here, we reported a novel three-dimensional hydrated vanadium pentoxide (V 2 O 5 · n H 2 O)/MXene composite via a simple one-step hydrothermal method. Owing to the unique structure and high electrical conductivity of MXene, V 2 O 5 · n H 2 O/Ti 3 C 2 T x MXene shows a remarkable electrochemical performance with a reversible capacity of 323 mAh g−1 at 0.1 A g−1 and exceptional rate capability (262 mAh g−1 at 1 A g−1 and 225 mAh g−1 at 2 A g−1) when used as the cathode for aqueous ZIBs. This work offers a new insight into fabricating novel vanadium oxide-based cathode material for aqueous ZIBs. [ABSTRACT FROM AUTHOR]

• FTOC/MXene was fabricated by combining MXene, C and (Fe 2.5 Ti 0.5) 1.04 O 4. • FTOC/MXene shows a unique two-dimensional architecture. • FTOC/MXene exhibits a superior rate performance as anode for LIBs. • The effects on restricting the volume expansion during cycling have been studied. The development of battery systems with high specific capacity and power density could fuel various energy-related applications from personal electronics to grid storage. (Fe 2.5 Ti 0.5) 1.04 O 4 possessing high theoretical specific capacity has been considered as a promising high rate anode material for lithium ion batteries due to the replacement of Fe3+ (0.64 Å) by Ti4+ (0.68 Å) with a larger radius to expand the interlayer space for ion intercalation. However, its extreme volume variation upon cycling as well as poor electrical conductivity hinder its further application. To tackle the above problems, in this work, we successfully synthesized two-dimensional (2D) (Fe 2.5 Ti 0.5) 1.04 O 4 /C/MXene architecture derived from Ti 3 C 2 T x MXene via solvo-hydrothermal, ultrasound hybridizing and high temperature annealing processes. The (Fe 2.5 Ti 0.5) 1.04 O 4 /C/MXene shows a high discharge capacity of 757.2 mAh g−1 after 800 cycles at a current density of 3 A g−1 with excellent rate performance. The superior electrochemical performances are triggered primarily by the incorporation of carbon and MXene into (Fe 2.5 Ti 0.5) 1.04 O 4 moiety to construct a 2D layered structure, which can improve the ion diffusion and electron transport. In addition, the synergistic contributions from diffusion controlled and capacitive processes for (Fe 2.5 Ti 0.5) 1.04 O 4 /C/MXene improve the ion diffusion rate and offer high specific capacity at high current density. The MXene-derived synthesis strategy in this work should be a promising pathway to synthesize other anode materials with 2D layered architecture for high performance lithium storage. [ABSTRACT FROM AUTHOR]

• Ternary NiCoFe-PBA/CNT was designed through composition/structural engineering. • Ternary NiCoFe-PBA/CNT shows extraordinary redox capacity and structural stability. • NiCoFe-PBA/CNT-based RCDI features a high desalination capacity of 140.8 mg g−1. • NiCoFe-PBA/CNT-based RCDI enjoys superior desalination rate and cycling stability. Prussian blue analogs (PBAs) have attracted considerable interest in capacitive deionization (CDI) as promising faradic electrode material candidates owing to their remarkable redox activity, non-toxic characteristics and cost-effectiveness. Yet, the desalination performance of the currently reported PBA-based CDI system falls far short of practical applications. Herein, the NiCoFe-PBA/carbon nanotube (CNT) composite is finely customized by a synergistic strategy of doping the Ni2+ into the CoFe-PBA and further employing conductive CNT as the interconnected framework for in-situ growth of NiCoFe-PBA particles, endowing the composite with excellent electrical conductivity, abundant redox-active sites, and structural stability. Moreover, we further coupled the NiCoFe-PBA/CNT composite with the rocking-chair CDI (RCDI) cell to avoid the capacity mismatch between the cathode and anode. As a result, the NiCoFe-PBA/CNT-based RCDI system achieves a high desalination capacity of 140.8 mg g−1 and a superior desalination rate of 0.51 mg g−1 s−1, which outperform most current PBA-based systems and are comparable to current state-of-the-art CDI systems. Besides, the system also exhibits excellent stability with almost no capacity degradation over 40 desalination cycles. This work highlights the importance of meticulous electrode material design and strategic CDI configurations in overcoming CDI bottlenecks, offering valuable insights for the advancement of future high-performance desalination systems. [ABSTRACT FROM AUTHOR]

Iron carbide (Fe 3 C) has become a significant type of anode material for lithium-ion batteries (LIBs) due to its intrinsic catalytic ability for the reversion of solid electrolyte interface (SEI) film. However, the low electrical conductivity and structural instability still hinder its practical application. The combination of Fe 3 C with highly conductive matrix is effective at addressing this issue. In this work, nano-Fe 3 C decorated N, S co-doped carbon nanotubes (Fe 3 C-NSC) was synthesized through a facile one-pot in-situ growth method. Benefiting from the synergetic effects between nano-Fe 3 C and N, S co-doped carbon nanotubes, Fe 3 C-NSC demonstrated an ultrahigh reversible capacity of 926 mAh g−1 at 100 mA g−1 after 100 cycles, and maintained a reversible capacity of 510.9 mAh g-1 at 500 mA g−1 after 900 cycles. Even when operated at −20 °C, Fe 3 C-NSC still delivered 373.4 mAh g−1 at 100 mA g−1 after 100 cycles. The strategy in this work should provide new insight into Fe 3 C-based anode of LIBs. [Display omitted] • Fe 3 C nanocrystals are decorated on N, S co-doped carbon nanotubes. • A facile one-pot in-situ growth strategy is developed. • The composite was evaluated as anode of lithium-ion batteries. • The composite demonstrates ultrahigh reversible capacity at both room and low temperature. [ABSTRACT FROM AUTHOR]

Co/Co 2 P@C Mott-Schottky electrocatalysts were successfully synthesized from Co-MOF and show excellent HER activity owing to the Mott-Schottky effect, synergy effect of Co and Co 2 P and porous carbon shell. Cobalt phosphides, as low cost and abundant non-noble materials for hydrogen evolution reaction (HER), are always constrained by their inferior charge transfer and sluggish intrinsic electrocatalytic kinetics. In this work, carbon-incorporated Co/Co 2 P microspheres (Co/Co 2 P@C) as a novel Mott–Schottky catalyst were synthesized successfully via carbonization and gradual phosphorization of Co based metal-organic frameworks. The unique merits, including Mott-Schottky effect at the interface formed between metal Co and semiconductor Co 2 P, the incorporated carbon-layer on the surface and the spherical structure endow Co/Co 2 P@C with favorable electrical conductivity, preferable kinetics and long-term stability when it was evaluated as electrocatalyst for HER in wide-pH range. As a result, the Co/Co 2 P@C with the optimized phosphorization degree delivers a benchmark current density of 10 mA cm−2 at the low overpotential of 192 and 158 mV in acidic and alkaline electrolytes, respectively, with a remarkable stability (CV cycling for 3000 cycles and continuous electrolysis at the overpotential of 200 mV for 48 h). Therefore, the as-designed Co/Co 2 P@C should be one of the most promising catalysts for HER application. [ABSTRACT FROM AUTHOR]

Metal oxide nanoparticles are one kind of important electrode materials for capacitive deionization (CDI) application. Unfortunately, most metal oxide materials usually exhibit poor electrical conductivity and often experience slow dissolution of metallic species, thereby resulting in limited desalination performance. Overcoming these obstacles still remains challenging due to the lack of synthetic approaches. Taking it into consideration, herein we proposed a dual confinement strategy to promote the CDI application of metal oxide nanoparticles. Nb 2 O 5 was synthesized as a typical example for designing metal oxide/MXene-reduced graphene oxide (rGO) derived from Nb 2 CT x MXene/graphene oxide (GO) under hydrothermal condition. In the hybrid, Nb 2 CT x and rGO serve as both the confinement agent and conductive support for Nb 2 O 5 nanoparticles, endowing Nb 2 O 5 /Nb 2 CT x -rGO with improved electronic conductivity and structural stability. As a result, the hybrid shows an outstanding desalination performance, including a NaCl adsorption capacity of 41.07 mg g−1, an ultra-fast average NaCl adsorption rate of 4.14 mg g−1 min−1 and excellent long-term cycling stability of 50 cycles (81 % desalination capacity retention rate). This work is expected to bring new insights in the synthesis of metal oxide materials for electrochemical desalination. [Display omitted] • A "dual-confinement" system of Nb 2 O 5 /MXene-rGO was constructed from Nb 2 CT x /GO. • Nb 2 O 5 /MXene-rGO was applied as electrode for hybrid capacitive deionization. • Nb 2 O 5 /MXene-rGO exhibited high desalination capacity/rate and good cycling stability. [ABSTRACT FROM AUTHOR]

The main challenge of using TiO 2 as anode for sodium-ion batteries (SIBs) is its inherent low electrical conductivity, which leads to its unsatisfied capacity, short cycle life and low initial Coulombic efficiency. Herein, we report that synergistically doped anatase TiO 2 nanotubes with Ni and N via a simple sol-gel process, subsequent alkali-thermal reaction, and final thermal treatment in NH 3 can optimize the relationship among the phase structure, electrical conductivity and sodium-ion diffusion kinetic performance of anatase TiO 2 to enhance its sodium-ion storage and transport performances. The resultant Ni and N co-doped anatase TiO 2 nanotubes (Ni-N/TNTs) exhibit a high charge capacity of 303 mA h g −1 after 500 cycles at a current density of 50 mA g −1 with an initial Coulombic efficiency of 65% and even at a high current density of 5 A g −1 , a capacity of 143 mA h g −1 is maintained after 8000 cycles with a capacity retention of ≥100%. The bandgap estimation, phase structure evolution, and electrochemical impedance spectroscopy analysis combined with the electrochemical test results indicate that the significantly improved sodium-ion storage and transport performances of Ni-N/TNTs should be mainly ascribed to the increased electrical conductivity, stable phase structure during the electrochemical processes, lower charge transfer resistance, and enhanced sodium-ion diffusion coefficient after Ni and N co-doping. The high capacity, improved Coulombic efficiency, excellent rate performance and long cycle life enable Ni-N/TNTs to be an applicable anode material for SIBs. [ABSTRACT FROM AUTHOR]

MoO 3 /reduced graphene oxide (MoO 3 /RGO) composites were successfully prepared via a facile one-step hydrothermal method, and evaluated as anode materials for sodium ion batteries (SIBs). The crystal structures, morphologies and electrochemical properties of the as-prepared samples were characterized by X-ray diffraction, field-emission scanning electron microscopy, cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge/discharge tests, respectively. The results show that the introduction of RGO can enhance the electrochemical performances of MoO 3 /RGO composites. MoO 3 /RGO composite with 6 wt% RGO delivers the highest reversible capacity of ~208 mA h g −1 at 50 mA g −1 after 50 cycles with good cycling stability and excellent rate performance for SIBs. The excellent sodium storage performance of MoO 3 /RGO should be attributed to the synergistic effect between MoO 3 and RGO, which offers the increased electrical conductivity, the facilitated electron transfer ability and the buffering of volume expansion. [ABSTRACT FROM AUTHOR]

• NiHCF/MXene was prepared via in situ close packing of NiHCF on MXene nano-stacking. • NiHCF/MXene exhibits 3D charge transfer pathway with unique vertical charge transfer. • NiHCF/MXene exhibits both excellent desalination capacity and high desalination rate. Prussian blue analogues (PBAs), as a kind of metal–organic framework–like materials, has attracted great attention in capacitive deionization (CDI) field due to excellent redox activity, but its desalination performance, especially its desalination rate, is greatly limited due to its poor electrical conductivity. Hybridization of PBAs with MXene can potentially solve this problem, but still remains intrinsic limitation, such as poor vertical charge transfer between nano-sheets. Herein, we engineered a three-dimensional (3D) charge transfer pathway in nickel hexacyanoferrate (NiHCF)/MXene through in situ close packing of NiHCF nanoparticles on MXene nano-stacking by electrostatic attraction. Compared to charge transfer mode in two-dimensional (2D) nano-sheets, 3D MXene nano-stacking can not only have excellent conductivity like MXene to provide horizonal charge transfer pathway alongside nano-sheets, but also possess unique vertical charge transfer pathway between nano-sheets. As a result, the NiHCF/MXene exhibits a superior desalination performance with a high desalination capacity of 30 mg g−1, ultrahigh desalination rate of 9.5 mg g−1 min−1 and good cycling stability over 30 cycles. This work demonstrates an effective way to address the poor CDI performance of nickel hexacyanoferrate nanoparticles by employing 3D MXene nano-stacking as charge transfer support, and is of significance to be applied for other nanoparticle materials. [ABSTRACT FROM AUTHOR]

Capacitive deionization (CDI) is an emerging desalination technology, offering an advisable route to fetch clean water due to its low energy consumption and environmental friendliness. Hybrid CDI (HCDI), proceeding through a faradic ion storage mechanism, is thought as the next generation of CDI due to its high desalination capacity and charge efficiency. However, current HCDI system is plagued by its low desalination rate and poor long-term stability due to the structural instability of the faradic materials. Herein, we developed an effective strategy via combining 2D MoS 2 nanoflakes with 2D MXene to construct a 3D "mutually supported" network architecture, in which MoS 2 nanoflakes could act as the "pillar" of the intrinsic structure of MXene, while MXene could offer structural reinforcement to prevent the structural agrgregation and enhance the electrical conductivity of the heterostructure. As a result, the HCDI system based on MoS 2 /MXene heterostructure electrode displays an outstanding desalination performance with a high desalination capacity of 23.98 mg g−1, outstanding desalination rate of 4.6 mg g−1 min−1 and superior cycling stability with only 4% desalination capacity degradation for over 100 cycles, indicating that our strategy should be a promising approach to achieve highly efficient HCDI. • 3D "mutually supported" MoS 2 /MXene was prepared by Combing 2D MXene and 2D MoS 2. • MoS 2 /MXene was applied as cathode for hybrid capacitive deionization. • MoS 2 /MXene exhibited good desalination performance and superior cycling stability. [ABSTRACT FROM AUTHOR]

[Display omitted] • 3D carbon-free nanoflower-like V 3 S 4 architecture was prepared via a facile method. • When used as anode of SIBs, V 3 S 4 exhibits superior sodium ion storage performance. • The electrochemical reaction mechanism of V 3 S 4 for sodium storage was investigated. Over the past years, transition metal sulfides, with remarkable redox reversibility, favorable electrical conductivity and superb theoretical capacity, have received considerable attention on the development of electrode materials that are capable of efficient and reversible storage of sodium ions. In this work, three-dimensional (3D) nanoflower-like V 3 S 4 was applied into sodium-ion batteries (SIBs) as anode, which was successfully synthesized via a facile solvothermal process with post-calcination treatment. The electrochemical measurements demonstrate that the as-prepared V 3 S 4 delivers a high reversible capacity of 499 mAh g−1 after 100 cycles at 0.1 A g−1. Furthermore, even at a high current density of 5 A g−1, the V 3 S 4 also exhibits an outstanding specific capacity of 299 mAh g−1 and a capacity retention rate of 58% compared with the capacity at 0.1 A g−1, which are superior to those of most vanadium sulfides for SIBs reported previously. Remarkably, the ultrahigh sodium-ion storage performance of V 3 S 4 should be ascribed to the unique nanoflower-like structure assembled by ultrathin nanosheets, which not only provides a large specific surface area, but also offers an adequate cushion to suppress the volume expansion during the sodiation-desodiation processes. More importantly, operando Raman spectra, ex-situ X-ray diffraction and ex-situ X-ray photoelectron spectroscopy were employed to demonstrate the evolution of the structure and chemical valence of V 3 S 4 , revealing that the high capacity of V 3 S 4 results from the cooperation of Na+ intercalation and conversion reaction. The findings of this study provide a better understanding on the sodium storage mechanism of V 3 S 4. [ABSTRACT FROM AUTHOR]

• NTP/M nanohybrid was synthesized by the transformation of Ti 3 C 2 MXene. • NTP/M nanohybrid was first applied for hybrid capacitive deionization. • NTP/M nanohybrid exhibited superior desalination performance and rate. The exploration and design of high-performance sodium-ion insertion host materials is of great significance to the development of hybrid capacitive deionization (HCDI). NaTi 2 (PO 4) 3 , abbreviated as NTP, is famous for its high theoretical sodium-ion storage performance, but due to the poor electrical conductivity, its desalination capacity has been largely limited. Herein we report the design and synthesis of NTP/MXene (NTP/M) nanohybrid by the transformation of Ti 3 C 2 MXene under solvothermal conditions. Due to its improved electrical conductivity and enhanced sodium-insertion ability with the introduction of MXene, the NTP/M nanohybrid shows an extraordinary desalination performance including a maximum deionization rate of 29.6 mg g−1 min−1, an ultrahigh desalination capacity of 128.6 mg g−1 and a stable cycling desalination ability, suggesting the promising application for practical HCDI. [ABSTRACT FROM AUTHOR]

• 3D TiO 2 @NC/Fe 7 S 8 was fabricated by combining urchin-like TiO 2 , NC and Fe 7 S 8. • TiO 2 @NC/Fe 7 S 8 exhibits excellent lithium storage capability as anode material. • The superior performance is due to synergistic effect between TiO 2 , NC and Fe 7 S 8. Nowadays, Ti 3 C 2 T x MXene has been reported to afford an ideal platform for the growth of TiO 2 by oxidation. Unfortunately, the TiO 2 derived from Ti 3 C 2 T x still possesses low lithium ion diffusion coefficient, poor electrical conductivity and relatively inferior capacity when used as anode of rechargeable lithium ion batteries (LIBs). In this work, three dimensional (3D) TiO 2 @nitrogen-doped carbon (NC)/Fe 7 S 8 composite was fabricated by a facile and simple hybrid strategy via in situ polymerization of pyrrole monomer with alkalized Ti 3 C 2 T x and subsequent vulcanization at 700 °C. When evaluated as an anode material for LIBs, the TiO 2 @NC/Fe 7 S 8 demonstrates a high reversible capacity (516 mAh g−1 after 100 cycles at 0.1 A g−1), excellent rate capability (337 mAh g−1 at 1 A g−1) and robust long cycling stability (282 mAh g−1 after 1000 cycles at 4 A g−1). The excellent electrochemical performances are contributed by the unique architecture of TiO 2 @NC/Fe 7 S 8 , where 3D urchin-like TiO 2 with good structural stability provides adequate space to increase the contact between electrode and electrolyte, shorten the lithium ion diffusion length and alleviate the volume change; nitrogen-doped carbon shell layer improves the electrical conductivity, facilitates the electron transport and prevents the aggregation for Fe 7 S 8 ; Fe 7 S 8 contributes high specific capacity during charge/discharge process. Importantly, the hybrid approach in this work enlightens the exploration on combing the MXene-derived oxides with other metal sulfides for promising applications in energy storage field. [ABSTRACT FROM AUTHOR]

• Ni 3 S 2 in-situ encapsulated in nitrogen doped carbon networks was fabricated. • The encapsulation improves the electrical and ionic conductivities of Ni 3 S 2 @NC. • The Ni 3 S 2 @NC exhibits excellent reversible capacity and superior cycling stability. Due to the conversion reaction induced high specific capacity, low cost and rich types, the interest on transition metal sulfides for efficient lithium storage has grown. Unfortunately, the intrinsically poor electrical conductivity and structure instability restrict their practical applications. Herein, an in-situ encapsulation strategy is developed to prepare the Ni 3 S 2 nanoparticles encapsulated in interconnected N-doped porous carbon (Ni 3 S 2 @NC) through a facile freeze-drying approach and subsequent in-situ conversion. When evaluated as anode material for lithium-ion batteries (LIBs), the as-prepared Ni 3 S 2 @NC exhibits a remarkable lithium storage performance, including high reversible capacity (1335.4 mAh g−1 after 100 cycles at 0.1 A g−1), superior rate capability (507.7 mAh g−1 at 4 A g−1) and excellent long-term cycling stability (961.4 mAh g−1 after 600 cycles at 0.5 A g−1 and 862.8 mAh g−1 after 600 cycles at 1 A g−1), displaying one of the best lithium storage performances among the Ni 3 S 2 -based electrodes reported by now. Such an excellent lithium storage performance should be attributed to the unique structure advantages of Ni 3 S 2 @NC inherited from the in-situ encapsulation strategy, such as tight combination, increased electrical conductivity, shortened ion diffusion distance and buffering matrix provided by N-doped porous carbon networks. Importantly, the facile design and engineering strategy should also be applied to explore other nanoarchitectures to boost their lithium storage performances. [ABSTRACT FROM AUTHOR]

Layered double hydroxides (LDHs) have shown remarkable potentials in supercapacitors for their highly-redox capacitance. However, the poor contact with substrate, slow charge transfer and ion diffusion, and low electrical conductivity limit their capacitor performance. In this work, a flexible free-standing supercapacitor was designed, with in-situ grown hollow-structured NiCo layered double hydroxide (H–NiCo LDH) as the active material based on a partial Ni ion substitution of Co ion in ZIF-67, and flexible carbon material as the substrate. Systematical investigation has been conducted in terms of nanostructures of the active material NiCo LDH (hollow or laminar structure) and flexible carbon substrates (acidified carbon cloth or acidified carbon fibers). A hollow-structured NiCo LDH@acidified carbon cloth (H–NiCo LDH@ACC) sample showed a promising capacity of 1377 mC/cm2 (3060 mF/cm2) at 1 mA/cm2, a low charge transfer resistance of 0.15 Ω, a capacity retention of 70% and a coulombic efficiency retention of 99% upon 10,000 cycles at 80 mA/cm2. PDMS-sealed solid-state H–NiCo LDH@ACC//AC devices were fabricated with an energy density of 0.0708 mWh/cm2 at a power density of 0.7 mW/cm2, with no obvious capacity decrease upon bending angles from 0° to 180°. SEM, EDS, XPS, and XRD analyses indicated the H–NiCo LDH has been in-situ grown on flexible carbon substrates. Hollow-structured LDH accelerated charge transfer and ion diffusion compared with a laminar-structured LDH. Acidified carbon cloth (ACC) showed better electrical conductivity compared with the biomass-derived acidified carbon fibers. Thus, a H–NiCo LDH@ACC is proposed as a promising candidate of a flexible supercapacitor. Image 1 • Hollow-structured NiCo layered double hydroxide (LDH) was in-situ grown on flexible carbon substrate for supercapacitor. • Hollow-structured LDH accelerated charge transfer and ion diffusion compared with a laminar-structured LDH. • Acidified carbon cloth showed better electrical conductivity compared with the acidified carbon fibers as substrate. [ABSTRACT FROM AUTHOR]