This work reports the synthesis of Ag@V₂O₅ nanocomposite electrodes via a three-dimensional direct ink writing (DIW) strategy, systematically evaluated for high-performance supercapacitor applications. DIW enables the precise extrusion and layer-by-layer assembly of a viscoelastic Ag@V₂O₅ ink, allowing for controlled electrode geometry, high mass loading, and the formation of an interconnected porous architecture that enhances electrolyte accessibility and charge transport. The incorporation of silver nanoparticles within the V₂O₅ matrix significantly improves electronic conductivity, facilitates rapid charge transfer, and introduces additional redox-active sites, while the DIW-fabricated 3D architecture ensures mechanical robustness and short ion/electron diffusion pathways. Electrochemical characterization reveals that the optimized Ag@V₂O₅ electrode delivers a high specific capacitance of 716.39 F g−1 at 1 A g−1, approximately 1.6 times higher than pristine V₂O₅, and retains 66.21% of its capacitance at 15 A g−1, demonstrating excellent rate capability. Cyclic voltammetry exhibits well-defined and symmetric redox peaks across scan rates of 5–100 mV s−1, confirming fast and reversible Faradaic processes, while galvanostatic charge–discharge measurements show minimal IR drop and high cyclic stability (89.78% over 5000 cycles). The superior electrochemical performance is attributed to the synergistic combination of Ag-mediated conductivity enhancement, structural integrity of the nanocomposite, and the high pseudocapacitive activity of V₂O₅. Furthermore, an asymmetric supercapacitor (ASC) was fabricated using Ag@V₂O₅ nanohybrid materials as the positive electrode and activated carbon (AC) as the negative electrode. The fabricated Ag@V₂O₅//AC ASC device attains a stable potential window of 1.6 V, a high energy density of 42.55 Wh kg−1 at a power density of 629.12 W kg−1 and maintains an energy density of 25.41 Wh kg−1 at a maximum power density of 7.208 kW kg−1. Additionally, the device demonstrates robust cycling stability, retaining 87.25% of its initial capacitance after 3000 charge–discharge cycles. This study paves the way for designing and developing advanced electrode architectures that deliver high energy and power densities for next-generation supercapacitors.

Direct ink writing (DIW) has emerged as a promising additive manufacturing technique for fabricating three-dimensional electrode architectures with controlled structural features and high design flexibility. MXenes (Ti3C2Tx), owing to their metallic conductivity, surface functionality, and viscoelastic properties, serve as excellent platforms for developing composite electrodes. In this work, we report for the first time the in-situ interfacing of 0D Cu-Ni-O-FPs/MXene as cathode and 0D α-Fe-O-FPs/MXene as anode materials, followed by their integration into a DIW-printed asymmetric supercapacitor (ASC). The Cu-Ni-O-FPs/MXene cathode exhibited an areal capacity of 1.23 mA h cm⁻² at 1 mA cm⁻², with a rate capability of 75.60 % at 80 mA cm⁻² and long-term cycling stability of 93.8 % after 10,000 cycles. The α-Fe-O-FPs/MXene anode delivered an areal capacity of 0.69 mA h cm⁻² at 1 mA cm⁻², demonstrating excellent charge-storage characteristics. When assembled, the DIW-printed Cu-Ni-O-FPs/MXene//α-Fe-O-FPs/MXene ASC achieved a remarkable energy density of 69.25 Wh kg⁻¹ at a power density of 380.1 W kg⁻¹, and 49.22 Wh kg⁻¹ at an ultra-high power density of 10,010.85 W kg⁻¹, along with 90.86 % retention after 10,000 cycles. This study establishes a new design paradigm for DIW-printed energy storage devices by leveraging the strong interfacial coupling between 0D pseudocapacitive nanoparticles and 2D MXene nanosheets. The unique 0D/2D pseudocapacitive-driven hybrid architectures ensure maximized redox contributions, minimized charge-transfer resistance, and well-balanced electrode kinetics.

With the consistent increase in global demand for renewable energy, microelectronics, and electric vehicles, the demand for lithium has surged drastically in recent years to ensure sustainable growth of respective sectors. Recovery of lithium particularly from seawater has emerged as a cutting-edge technology to strengthen lithium resources. Since the innovation of two-dimensional (2D) materials, 2D materials-driven nanofiltration (NF) membranes have been on the top priority for lithium recovery, mainly due to their cost-effectiveness and energy efficiency. The most phenomenal aspect associated with 2D materials nanofiltration process is that exceptional ions and water permeation phenomena have been attained. These results are achieved mainly due to the existence of a synergistic effect between controlled pore size (stacking space available between adjacent layers) and surface properties of nanopores/nanochannels developed in membranes. In this review report, we have outlined and discussed various 2D materials including graphene, graphene oxide (GO), MXene (Ti3C2X), hexagonal-boron nitride (h-BN), metal-organic framework, metal covalent framework, and transition metal dichalcogenides (TMDs) deployed for construction of nanofiltration membranes along with their attained monovalent metal ions rejection outcomes, Li+ ions in particular. Various strategies (i.e., defect engineering, cation regulations, and modification of surface functional groups) have been explained in detail in order to create nanopores into nanosheets and to tune the interlayer spacing of 2D nanofiltration membranes. Moreover, 2D materials composite nanofiltration membranes with improved metal ion rejection rates, hydrophobicity, enhanced structural integrity in varied pH solutions, and non-swelling characteristics have also been discussed. Finally, to promote the development of 2D materials-driven nanofiltration membranes with further enhanced lithium-ion recovery rates, rational design of membrane structures, relevant challenges, and future perspectives are insightfully addressed.

A novel binder-free copper oxide@nickel sulfide (CuO@NiS) composite electrode was successfully synthesized on Ni foam via a two-step hydrothermal method for high-performance supercapacitor applications. The hierarchical morphology of the CuO@NiS composite, consisting of CuO microspheres decorated with NiS nanoparticles, offers a large surface area and facilitates electrolyte ion diffusion. The electrode exhibited a high specific capacity of 130.09 mA h g- 1 at 1 A g- 1 and excellent cycling stability with 92.64 % capacity retention after 5000 cycles. A hybrid supercapacitor (HSC) assembled with CuO@NiS and activated carbon (AC) electrodes demonstrated a wide operating voltage of 1.6 V, a maximum energy density of 33.96 W h kg- 1 at 368.69 W kg- 1, and excellent cycling stability of 94.57 % over 5000 cycles. The superior performance of the CuO@NiS composite electrode is attributed to its unique morphology, enhanced electrolyte accessibility, and synergistic interaction between CuO and NiS components. These findings highlight the potential of CuO@NiS as a promising electrode material for high-performance supercapacitors.

Flexible substrates are essential for advancing energy storage materials in portable and wearable devices. Carbon cloth is a promising option due to its flexibility and lightweight properties, but its high electrical resistance and hydrophobic surface present challenges for solution-based electrolytes. To overcome these issues, a surface modification technique was developed that coats carbon cloth with dopamine and subsequently carbonizes it. This process enhances hydrophilicity while preserving the sp2 carbon structure, significantly improving electrical conductivity. The chemical bath deposition of Ni(OH)2 onto the carbonized polydopamine-coated carbon cloth produced a uniform layer that increased specific capacitance dramatically. At a current density of 1 A/g, the specific capacitance reached 1100F/g, compared to 919F/g for Ni(OH)2 on unmodified carbon cloth. Furthermore, the electrodes maintained high specific capacitance at higher current densities, showcasing superior rate capability. Overall, carbonized polydopamine layers effectively reduce electrical resistivity and hydrophobicity, enhancing the performance of carbon-based materials for energy storage applications.

A nanostructured NixFeyCuz(CO3)(OH)2 electrode with a large surface area was deposited on a Ni-foam substrate using a facile hydrothermal method. The well-organized microscopic and free-standing nano-sized ternary metal compounds exhibited high electrical conductivity and competent ion transport ability. This composite is particularly attractive for high-performance power-storage systems owing to its binder-free nature and exceptional value as a current-carrying electrode. Ternary electrodes containing three transition metals have a higher entropy than binary electrodes, which reduces the movement distance of ions on the electrode surface and enhances key electrochemical advantages, thereby providing a high specific capacitance with durability and cycling stability when coated with a highly conductive electrochemical pattern. The NixFeyCuz(CO3)(OH)2 compound demonstrated remarkable specific surface area of 106 m2 g-1 and high specific capacities of 271.8 and 75.2 mAh g-1 at current densities of 3 and 15 A g-1. In addition, an asymmetric supercapacitor fabricated with the NixFeyCuz(CO3)(OH)2 compound as the positive electrode and graphene as the negative electrode exhibited a high energy density of 55.1 W h kg-1 at power and current densities of 398.5 W kg-1 and 2 A g-1, respectively, as well as a remarkable cycling stability of 84.3 %, which was maintained following 10,000 long cycles.

High-performance electrochemical supercapacitors are highly needed to meet the fast-growing needs of the electronics industry. However, achieving the ideal electrochemical performance of asymmetric supercapacitors (ASC) devices are impacted by the poor specific capacitance, restrained rate capability, and inferior cycling stability of both anode and cathode materials. Herein, we have reported ASC device completely based on highly electroactive pseudocapacitive electrode materials. Novel zero dimensional (0D) copper-iron-phosphate (Cu3Fe4(PO4)(6)) nanoparticles are synthesized through a facile hydrothermal method and have been deployed as an anode material. Moreover, zinc molybdenum oxide (ZnMoO4) nanorods with unique triangular morphology have been utilized as a cathode material. The Cu3Fe4(PO4)(6) electrode exhibits a high specific capacitances of 996.8 F g(-1) at 2 A g(-1), whereas the ZnMoO4 electrode achieves a maximum specific capacitance of 1113.7 F g(-1) at the same current density. In the existence of reported electrode materials, Cu3Fe4(PO4)(6)//ZnMoO4 asymmetric supercapacitor device displays an outstanding energy density of 39.1 Wh kg(-1) at a power density of 657.31 W kg(-1). The as-constructed ASC device consists of 0D Cu3Fe4(PO4)(6) nanoparticles and ZnMoO4 triangular nanorods has shown enriched electrochemical potential for the development of sustainable energy storage systems.

Two-dimensional (2D) materials display a unique set of physical/chemical properties and are considered potential building blocks for the manufacturing of microstructured materials for a number of applications. Prominent applications range from advanced electronics to miniaturized electrochemical energy storage devices (EESDs). Herein, we present a comprehensive and critical review of the recent developments in design and microfabrication of 2D-driven microscale electrodes for three-dimensional (3D)-printed micro-supercapacitors and micro-batteries. Firstly, we systematically discuss the advantages and disadvantages associated with various microfabrication techniques such as stereolithography, fused deposition modeling, inkjet printing, and direct ink writing. Next, key parameters disclosing the relationship between the characteristics of 2D-based materials and extrusion-driven 3D printing process for the development of versatile and sustainable EESDs are highlighted. 2D materials utilized for the construction of microelectrodes for supercapacitors (e.g., electric double layer capacitors (EDLCs), pseudocapacitors, and hybrid capacitors) and batteries (e.g., Li-based systems and next-generation systems, e.g., sodium-ion batteries and zinc-ion batteries) along with their prominent electrochemical contributions in relation to obtained 3D-printed architectures are discussed in detail. To promote the development of 2D materials-driven high-performance microscale EESDs, the relevant challenges and future research opportunities are also addressed.

0D@2D heterostructures constituted by binary transition metal sulfides@transition metal carbides can illustrate the combined advantages of each material with their improved electrochemical performance for energy storage devices. 2D transition metal carbides (MXene -Ti3C2) have presented themselves as the most appropriate candidates for the construction of lower-dimensional 0D -like electroactive nanoparticles (NPs). Due to the high theoretical capacity values and versatile valence states, the molybdenum incorporated mixed metal sulfides ((Mox-Mn)Sy) nanoparticles decorated over 2D Ti3C2 sheets are reported for Li-ion battery and asymmetric supercapacitor. A uniquely designed (Mox-Mn)Sy-NPs@MXene hybrid material displays a high Li-ion storage capacity of up to 698 mA h g-1 at 50 mA g-1, and a commendable areal capacity performance (-1.27 mA h cm-2 at 2 mA cm-2) for supercapacitor, along with outstanding capacity retention at higher current density and stable cycling performance. Furthermore, a 0D@2D (Mo-Fe7)Sx-NPs@MXene hybrid material is utilized as anode material to construct a coin cell-like (Mox-Mn)Sy-NPs@MXene//(Mo-Fe7)Sx-NPs@MXene asymmetric super -capacitor (ASC) device. A high-voltage (-1.90 V) ASC device based on unique 0D@2D heterostructures displays an ultra-high energy density of 78.8 W h Kg-1 at a power density of 634.63 W Kg-1 along with maximum specific capacity retention and cycling stability performance. This study emphasizes the importance of 0D@2D based heterostructure materials for the development of efficient energy storage devices.

The electrochemical performance of printed asymmetric supercapacitors can be improved by designing and implementing properly engineered anode and cathode electrode materials with enriched redox kinetics. How-ever, the development of high-performance printed anode/cathode electrodes with three-dimensional (3D) structures is crucial task. Direct Ink Writing (DIW) is a versatile advanced manufacturing technology for developing 3D complex electrode architectures for efficient energy storage devices. In addition, replacing conventional electric double-layer capacitors as anode materials with redox-driven electrodes can significantly improve the specific capacitance and energy density of asymmetric supercapacitors. Herein, for the first time, we report a 0D@2D silver-nanoparticles@Ti3C2 DIW printed anode material for asymmetric supercapacitors. The Ag-NPs@Ti3C2 hybrid material contributes a high-specific capacitance of 368.56 F g  1 at a current density of 1 A g  1 with a minimum specific capacitance of 233.84 F g  1 at 10 A g  1. To assemble the asymmetric super-capacitor device, 0D@2D MnO2@Ti3C2 DIW printed cathode is implemented, which displays excellent electro-chemical performance in terms of specific capacitance (474.45 F g  1 at 1 A g  1). In the existence of all-printed advanced anode (Ag@Ti3C2) and cathode (MnO2@Ti3C2) materials, the asymmetric supercapacitor device shows a maximum energy density of 38.16 Wh kg  1 at a power density of 800 W kg  1, with a capacitance retention of up to 91.27 % after 5000 cycles. Thus, the application of DIW printed electrode materials with optimum electrochemical contributions provides new avenues for the development of high-performance energy storage devices.

The design of electrode materials for improved electrochemical properties and stable geometric config-uration is known as effective research in developing the electrochemical capability of supercapacitors (SCs). However, there is a difficulty in designing innovative composite material with excellent electrical conductivity and superior specific capacity by way of low cost and easy synthesis process. Herein, for the first time, a stable Sn-Co-S/MXene hybrid material is fabricated through the electrochemical assembly by combining positively charged ultrafine Sn-Co-S nanoparticles (NPs) and negatively charged 2D Ti3C2Tx (MXene) sheets due to electrostatic interaction. The Sn-Co-S/MXene hybrid material has displayed excel-lent electrochemical performance with an ultrahigh specific capacity of 305.71 mA h gm-1 at 1 A g-1 and capacity retention of 94.8% after 10, 000 charge-discharge cycles. The Sn-Co-S/MXene hybrid material of high electrochemical performance has improved charge transfer kinetics during the charge-discharge process, due to the synergistic coupling effect between ultrafine Sn-Co-S nanoparticles and MXene sheets. Furthermore, the Sn-Co-S/MXene//activated carbon (AC) asymmetric supercapacitor (ASC) device has been configured with the assistance of Sn-Co-S/MXene as cathode and AC as anode materials. The Sn-Co-S/MXene//AC ASC device exhibits a stable potential window of 1.7 V, a high specific capacitance of 108.50F g-1 at 1 A g-1, and an energy density of 43.55Wh kg-1 at a power density of 0.83 kW kg-1. This study validates the design and application of highly electroactive Sn-Co-S/MXene hybrid electrode material for ultrastable asymmetric supercapacitors. & COPY; 2023 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

Hybrid supercapacitors (HSCs) have currently gained vital attention as promising energy storage devices owing to their higher energy density than conventional supercapacitors, not scarifying their power density, fast charging-discharging ability, and long cycle life. Herein, we report an inclusive review about the recent advances in the anion storage of aqueous and non-aqueous HSCs, where the energy density can be further improved by means of the enhanced capacitance and enlarged cell voltage. Furthermore, the anion storage mechanisms of HSCs, such as adsorption, intercalation, conversion, and alloying types are discussed, and the role of various anion carriers in various aqueous and non-aqueous electrolytes are also addressed. The anion-storing materials, electrolyte properties, and the corresponding electro-chemical performances of the HSCs are collected in terms of the types of anion carriers and electrolyte solutions. Finally, we provide conclusive limitations and decisive future perspectives for the practical anion storing HSCs.(c) 2023 Elsevier Ltd. All rights reserved.

Encapsulation of transitional metal selenides within the porous nanocarbon network is regarded as a highly advantageous strategy for exploring anodes with enhanced capacity, cycle-to-cycle stability, and long-lasting practical operation capability for Li+ storage. Herein, Fe-mediated selenide nanoparticles were encapsulated within eco-friendly carboxymethylcellulose (CMC)-derived porous carbon (FeSe2@PC) utilizing a mildly sol-gel process and in-situ self-transformation strategy, achieving a feasible capacity and relatively durable structure. The FeSe2@PC anode with square-built Li+/e- diffusion pathway exhibits a comparatively high reversible capacity of up to 758 mAh g-1 at 0.1 A g-1 and relatively good cycling stability, with a capacity retention of 83% after 500 cycles at 1 A g-1 in half cells. FeSe2@PC//LiMn2O4 full cells also demonstrate above-average electrochemical performance when paired with a LiMn2O4 cathode. The nanoconfinement electrode configuration, with interconnected external/internal carbon shell/FeSe2 nanoparticles, can not only provide good electrical conductivity and buffering capacity for volume changes but also facilitate electrolyte infiltration and surface/near-surface interactions between electroactive FeSe2 and Li+. Kinetic analysis by cyclic voltammetry at different scan rates, galvanostatic intermittent titration technique, and electrochemical impedance spectroscopy at different cycles/voltages indicates exceptional Li+/e- transport kinetics. Ex-situ Raman scattering patterns at various potentials during the lithiation/delithiation processes denote the detailed reaction mechanisms and reversible phase transformation in the FeSe2@PC electrode. Employing green and eco-friendly materials in energy storage is crucial for advancing sustainable energy technologies, and the FeSe2@PC nanocomposite demonstrated in this study offers promising potential towards this objective.

Iron fluoride is an excellent cathode material for alkali metal-ion batteries due to its high operating voltage and extremely high specific discharge capacity. To overcome its voltage hysteresis and compensate for capacity fading due to volume change and electrode dissolution, a FeF3.0.33H(2)O@carbon nanocomposite with a pomegranate-like structure (FeF3.0.33H(2)O@C) is designed and successfully synthesized via hydrothermal synthesis followed by a solid-phase process. The FeF3.0.33H(2)O@C nanocomposite derived from pomegranate structure effectively can reduce electrode polarization via its unique hierarchical carbon-coated architecture. Additionally, combining other structural advantages (e.g., coordination of volume expansion, reduction of Fe dissolution, and inhibition of nanoparticle coarsening) can result in high reversibility and rate performance. For Lithium-ion battery, the nanocomposite cathode demonstrates a discharging capacity of 225 mA h g-1 at 0.1C, as well as an excellent long-cycle performance with a capacity retention rate of 93% after 200 cycles. When the cathode materials are used in sodium-ion batteries, the nanocomposite cathode achieves an exceptionally high energy density of 1015 Wh kg-1, which is more than twice that of the commercial LiCoO2 cathode (504 Wh kg-1).

Using a facile ultra-sonication method, Ag nanoparticles are embedded into TiO2 nanoparticles, and the as-developed composite material is 3D printed through direct ink writing (DIW) process as an electrode material for supercapacitor. The as-printed TiO2-Ag composite electrode displayed a lower contact angle value of 32.2 degrees, with higher surface energy of 76.32 mJ m(-2). The electrochemical performance of the TiO2 nanoparticles incorporated with silver nano-powder is improved significantly in-comparison to pristine TiO2 nanoparticles. The significant improvement in the electrochemical performance of the TiO2 nanoparticles with the incorporated silver nano-powder is due to the synergistic interaction between the TiO2 nanoparticles and the silver nano-powder developed through sonochemical process. The plain TiO2 and TiO2-Ag composite printed electrode revealed a maximum specific capacitance (specific capacity) values of 148.43 (56.84 mA h mg(-1)) and 257.8 (122.96 mA h mg(-1)) F g(-1) at 1 A g(-1), respectively. TiO2-Ag composite printed electrode also maintained a capacitance retention of 58.3% at a higher current density of 10 A g(-1). The electrochemical impedance spectroscopy study also confirms that the incorporation of silver nano-powder into TiO2 nanoparticles reduces charge transfer resistance (R-ct). The TiO2-Ag nanocomposite electrode shows excellent long-term cycling stability with 96% of capacitance retention after 3,000 continuous GCD cycles. Moreover, TiO2-Ag//AC based asymmetric supercapacitor device is developed which delivers a high energy density of 26.72 W h Kg(-1) at minimum power density of 655.61 W kg(-1). These results indicate a high potential of the as-printed TiO2-Ag composite electrode material for energy storage applications.

Uniform amorphous FePO4 nanospheres are successfully synthesized by a simple hydrothermal process. The phase and chemical composition of the sample are, respectively, obtained from the X-ray diffraction (XRD) data of the original sample and the XRD data of the substance after annealing. The as-prepared sample is composed of uniform nanospheres with a diameter of 220 nm. The necessity of an amorphous structure for the cathode application of this material is analyzed through the crystal-phase structure diagram. The transformation between the amorphous structure and the microcrystalline structure can be realized in the battery during the charging and discharging process. Electrochemical results show that amorphous iron phosphate shows good sodium-ion storage performances. The amorphous structure of iron phosphate is very necessary in the sodium-ion battery system with sodium iron phosphate as the positive electrode.

Well-organized, independent nanoscale binary metal oxides exhibit high electrical conductivity and good ion transportability. In this study, a nickel-cobalt oxide (NiCo2O4) nanoparticle electrode was synthesized on Ni foam with a large surface area. Such a composite material is valuable as a binder-free and excellent current-carrying electrode material. Hence, it is particularly attractive for high-performance energy storage systems. NiCo2O4 nanowires were fabricated via a simple chemical bath deposition process. Consequently, the NiCo2O4 electrodes exhibited a remarkable specific capacity of 342.5 mA h g(-1) at the current density of 3 A g(-1) and cycling stability of 80.7%, which was maintained following 10,000 long-cycles at 5 A g(-1). In addition, an asymmetric super -capacitor (NiCo2O4//graphite) device comprising of NiCo2O4 as a positive electrode and graphite as a negative electrode was fabricated. The NiCo2O4//graphite asymmetric supercapacitor has the highest energy density of 45.8 W h kg(-1), and an excellent power density of approximately 5689 W h kg(-1). Furthermore, NiCo2O4// graphite device delivered sufficient capacitive power to enlighten a red LED indicator. The excellent electro-chemical performance of the asymmetric supercapacitor device can be attributed to the high specific surface area of the cathode electrode material and its enriched redox kinetics. This paper presents an easy and environmentally-friendly procedure for fabricating a compound electrode material for an asymmetric super -capacitor. It is expected that this novel high-performance electrode can stimulate new directions in the development of efficient energy storage.

Modern electronics industries-based on portable and wearable devices, urgently needed the design and fabri-cation of high-performance flexible electrochemical supercapacitors. However, the low specific capacitance and deprived rate-capability of cathode and anode electrode materials are two prominent hurdles in obtaining the optimal electrochemical performance of flexible asymmetric supercapacitors (ASCs) devices. Herein, for the first time, metal-organic framework-derived shell@core and MXene-supported shell@core strategies are reported to fabricate high-performance cathode and anode electrode materials, respectively for sustainable flexible asym-metric supercapacitor. The NiS@Co-Mo-LDHs shell@core as cathode and Co-Fe-O-nanoparticles@MXene as anode electrodes demonstrate high areal capacities of 1.43 and 0.949 mA h cm-2, respectively at a current density of 1 mA cm-2. Benefiting from the commendable individual electrochemical performances of the cathode and anode electrode materials, the as-assembled NiS@Co-Mo-LDHs//Co-Fe-O@MXene flexible all-solid-state asymmetric supercapacitor (FSS-ASC) device exhibits an excellent energy density of 90.2 W h Kg -1 with supe-rior capacitance retention up-to 90.6 % after 10,000 cycles. Furthermore, after flexibility testing, the NiS@-Co-Mo-LDHs//Co-Fe-O@MXene FSS-ASC device also retains excellent electrochemical properties. These electrochemical findings reveal that the NiS@Co-Mo-LDHs shell@core and Co-Fe-O@MXene shell@core elec-trode materials are the appropriate candidates for the development of high-performance flexible energy storage devices.

FeF3·0.33H2O@CNS (Honeycomb-like Carbon Nanosheets) with high pseudocapacitive contribution demonstrates excellent rate and cycle performance as Li-ion cathode materials.