A novel amorphous MoS2/MoO3/nitrogen-doped carbon composite has been successfully synthesized for the first time. The synthesis strategy only involves a facile reaction that partially sulfurizes organic–inorganic hybrid material Mo3O10 (C2H10N2) (named as MoOx/ethylenediamine) nanowire precursors at low temperature (300 °C). It is more interesting that such amorphous composites as lithium ion battery (LIB) and sodium ion battery (SIB) anode electrodes showed much better electrochemical properties than those of most previously reported molybdenum-based materials with crystal structure. For example, the amorphous composite electrode for LIBs can reach up to 1253.3 mA h g–1 at a current density of 100 mA g–1 after 50 cycles and still retain 887.5 mA h g–1 at 1000 mA g–1 after 350 cycles. Similarly, for SIBs, it also retains 538.7 mA h g–1 after 200 cycles at 300 mA g–1 and maintains 339.9 mA h g–1 at 1000 mA g–1 after 220 cycles, corresponding to a capacity retention of nearly 100%. In addition, the amorphous composite electrode exhibits superior rate performance for LIBs and SIBs. Such superior electrochemical performance may be attributed to the following: (1) The carbonaceous matrix can enhance the conductivity of the amorphous composite. (2) Heteroatom, such as N, doping within this unique compositional feature can increase the active ion absorption sites on the amorphous composite surface benefitting the insertion/extraction of lithium/sodium ions. (3) The hybrid nanomaterials could provide plenty of diffusion channels for ions during the insertion/extraction process. (4) The 1D chain structure reduces the transfer distance of lithium/sodium ions into/from the electrode.Keywords: Amorphous; Lithium ions batteries; MoS2/MoO3; Sodium ion batteries;

•Hierarchical MoO2 multi-shell structures are designed as anode material for lithium ion batteries.•Multi-shell structures are synthesized by a template-free one-pot solvothermal method.•Synthesizing well-designed multi-shell structures provides potential solution to improve the electrochemical performance for energy application.A hierarchical multi-shell structure of MoO2 is synthesized through a template-free one-pot solvothermal method. The relative MoO2 electrode exhibits high reversible specific capacity of 780 mA h g−1 after 40 cycles, good stability, high capacity retention and improved rate performance in the lithium ion battery application. This material has a unique hierarchical architecture which is a combination of pure hollow structure and core-shell structure. Such a hierarchical multi-shell structure can not only amplify active mass-electrolyte contact area and minimizes lithium ion diffusion path, but also provides a unique interstitial void space to relieve the huge volume change of material. Materials with a hierarchical multi-shell structure are expected to be promising candidates in lithium ion batteries application.Download high-res image (178KB)Download full-size image

•We reported an anode material for NIBs, Ni-MOF-derived nickel sulfide(NiS2).•The synthesis strategy involves a novel method.•The synthesized Ni-MOF-derived NiS2 showed a hierarchical durian-like nanostructure made of around 10 nm nanoparticles.•The synthesized NiS2 nanostructure electrode exhibits excellent electrochemical performance.An anode material for sodium-ion batteries, Ni-Metal-Organic Frameworks (MOFs)-derived nickel sulfide (NiS2), is first reported. The synthesis strategy involves a novel method in which Ni-based MOFs is fabricated as precursor and then sulfured by sublimed sulfur in solid phase reaction. The as synthesized Ni-MOFs-derived NiS2 shows a hierarchical durian-like nanostructure made of nanoparticles with the diameter of around 10 nm and amorphous carbon with 3 dimensional conductive net skeleton. Moreover, due to the novel hierarchical nanostructure, sodium ions are able to easily insert/extract into/from the active material. As a result, the as synthesized Ni-MOF-derived NiS2 nanostructure electrode exhibits high specific capacity and excellent rate performance. We believe that the hierarchical Ni-MOFs-derived NiS2 nanoparticles will be one of the most promising electrode materials for sodium-ion batteries.

•Microspherical HxMoO3/C precursors are synthesized via a heterocatalytic reaction.•The existence of H· in the precursors can facilitate the oxycarbide transformation.•Nanocrystalline MoO2 matrix ensures a rapid insertion–conversion transformation.•The extrinsic pseudocapacitive behaviour benefits cycling and rate performance.•Hybridization with Mo2CTx can overcome some limitations of MoO2/C composites.Uniform nano/micro-spherical MoO2/Mo2CTx (T = O) heterostructures have been synthesized through a heterocatalytic reaction with subsequent facile calcinations. Given the high activity of HxMoO3/C precursors, this strategy opens a low-temperature route to realize the fabrication of nanocrystalline MoO2/Mo2CTx heterostructures, leading to achieve rapidly activated conversion reaction and extrinsic pseudocapacitive behaviour. Rather than carbon, highly conductive Mo2CTx decreases the charge transfer resistance in MoO2 and maintains its structural stability upon lithiation/delithiation, ensuring the heterostructures with excellent cyclability (e.g., up to 833 mA h g⁻1 at 100 mA g⁻1 for 160 cycles with 95% capacity retention) and high rate capability (e.g., 665 mA h g⁻1 at 1 A g⁻1). Additionally, owing to the carbon-free characteristic, the secondary nano/microstructure feature and the suppressed surface oxidation trait, MoO2/Mo2CTx heterostructures, therefore, can deliver an improved initial Coulombic efficiency (e.g., up to 78% at 100 mA g⁻1). The present oxycarbide transformation and hybridization strategies are facile but effective, and they are very promising to be applied to converting other oxides–carbon composites into oxides/carbides heterostructures towards achieving higher electrochemical performance.Download high-res image (610KB)Download full-size image

AbstractUltrafine CoP nanoparticles embedded in nitrogen-doped carbon matrix derived from zeolitic imidazolate framework 67 (ZIF-67) template are first obtained. The synthesis strategy only involves a facile method in which ZIF-67 precursor is phosphided under argon atmosphere. Such novel nanostructure consists of ultrafine CoP nanoparticles and N-doped carbon matrix which greatly shorten the transport length of lithium ions, effectively buffer the volume expansion during the lithiation/delithiation process, and improve the electrical conductivity. Owing to their unique architecture characteristics, the active material exhibits a superior specific capacity of 522.6 mAh g−1 after 750 cycles at a current density of 200 mA g−1 and outstanding cycling stability up to 2000 cycles at a high current density of 500 mA g−1. In addition, the active material exhibits superior rate capability.

•A novel core–shell MoO2/C nanospheres embedded in bubble sheet-like carbon film electrode materials are designed.•This unique design can be widely applied to electrode materials suffering from huge volume change during cycling.•Interconnected carbon networks can improve the conductivity and the buffer volume expansion.The core-shell MoO2/C hollow spheres encapsulated by interwoven carbon networks were synthesized by a simple solvothermal process followed by an anneal procedure. This core–shell MoO2/C nanospheres embedded in bubble sheet-like carbon film (MCB) electrodes exhibit outstanding electrochemical performance as anodes for LIBs. It can deliver a stable specific capacity of ∼500 mA h g−1 at 1C for 300 cycles, and an excellent rate capability: retaining of 275.2 mA h g−1 at 3C, as well as backing to the same stage when the current density is reduced to 0.2C.Download high-res image (95KB)Download full-size image

Flexible batteries have attracted much attention in recent years due to their promising applications in flexible displays, portable consumer electronic devices, and thin-film-based electronics. However, their practical applications are still limited by their low active material mass-loading in flexible electrodes and poor lithium storage performances. In this work, we have successfully grown highly crystalline VO2 nanobelt arrays on carbon fiber cloth (CFC) for the first time. The strategy only involves a facile one-pot solvothermal method. As binder-free flexible electrodes for LIBs, even with active material mass loading dramatically reaching up to 5.2 mg per square centimeter, such a novel CFC@VO2 (B) nanobelt array cathode electrode still exhibits a specific capacity of 145 mA h g−1 (90% of theoretical capacity), excellent cyclability with capacity retention over 90% after 200 cycles at ∼9C (1000 mA g−1), and high rate capability at high current densities up to ∼20C (2000 mA g−1). Such an excellent cathode material is very desirable in high-power flexible LIBs. The effective combination of CFC and a high areal mass loading of active materials described in this paper is a feasible and effective solution to design high-performance flexible batteries, especially high-power flexible batteries.

Yolk–shell carbon encapsulated tin (Sn@C) eggette-like compounds (SCE) have been synthesized by a facile method. The SCE structures consist of tin cores covered by carbon membrane networks with extra voids between the carbon shell and tin cores. The novel nanoarchitectures exhibit high electrochemical performance in both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). As anodes for LIBs, the SCE electrodes exhibit a specific capacity of ∼850 mA h g–1 at 0.1 C (100 mA g–1) and high rate capability (∼450 mA h g–1 remains) at high current densities up to 5 C (5000 mA g–1). For SIBs, the SCE electrodes show a specific capacity of ∼400 mA h g–1 at 0.1 C and high rate capacity (∼150 mA h g–1 remains) at high current densities up to 5 C (5000 mA g–1).Keywords: eggette-like compounds; lithium-ion batteries; Sn; sodium-ion batteries; yolk−shell structure

Parallelly aligned NiO hierarchical nanostructures were fabricated using a templated self-assembly method followed by calcinations, where rationally employed pluronic triblock copolymers (P123) are acting as molecular templates for geometrical manipulation of nanocrystals and short-chain alcohols are acting as cosolvents and cosurfactants. Such aligned nanostructure is constructed orderly with several ultrathin two-dimensional (2D) nanosheet subunits with an exceptionally small thickness of only 3 nm in a high degree of orientation and separation. Moreover, the number of assembled nanosheets in a unit can be tuned by changing the concentration of the involving P123. This is the first time to synthesize highly hierarchically ordered and bilaterally symmetrical nanostructures, distributed in diameter of around 200–300 nm, via self-assembly in the liquid phase without solid substrates. The as-synthesized NiO delivered high capacitances of 418 F/g at the current density of 2 A/g with well cycling stability (still maintained 85% after 2000 cycles) and 333 F/g at 10 A/g in rates performance after 60 cycles. These fine electrochemical performances are supposed to be attributed to the hierarchical structures with high specific surface area (SSA, ∼164.87 m2/g) and ordered multilevel mesopores, which facilitate the electrolyte accessibility and provide more active sites for redox reaction.Keywords: high-rate performance; layers controllable; multilevel mesopores; P123-assisted self-assembly; parallelly aligned NiO hierarchical nanostructures; supercapacitor; ultrathin nanosheet subunits

•A unique yolk-shell structured SnO2@void@C nanowire has been designed.•This is a unique structure as anode materials for both LIBs and SIBs.•This structure delivers significantly improved electrochemical performance.Various yolk-shell structured particles designed for large volume expansion materials for lithium-ion storage have been reported, the cycle stability and coulombic efficiency can be effectively improved through such structure design. SnO2 has high theoretical capacity of 1494 mA h g−1 and 1378 mA h g−1 for lithium and sodium storage, respectively. The large volume expansion problem of SnO2 has long been considered as the primary reason for the capacity fading of SnO2 based anode materials. In this paper, the yolk-shell structured SnO2 porous nanowire has been designed, and this unique yolk-shell structure is reported as anode materials for lithium and sodium-ion storage for the first time. The yolk-shell structured porous nanowires deliver significantly improved cycle stability and coulombic efficiency as active material for both lithium and sodium-ion storage compared with that of pure SnO2 porous nanowires. It exhibits a high and stable capacity of 1150 mA h g−1 at current density of 200 mA g−1 for lithium-ion storage, and a capacity of 401 mA h g−1 at current density of 50 mA g−1 after 50 cycles for sodium-ion storage.

•Mo2N with high density of nanopores has been synthesized on gram-scale.•The Mo2N nanobelts exhibited high electrocatalytic activity in alkaline electrolyte.•The Mo2N also exhibited high performance as supercapacitor electrode material.•The electrochemical perperties results from high surface area and good crystallinity.Replacing precious and nondurable Pt catalysts with cheap materials is a key issue for commercialization of fuel cells. Intriguing transition metal nitrides (TMNs) have attracted great attentions as promising economic alternatives to Pt catalysts due to their noble metal-like properties. However, most of as-synthesized TMNs are nanoparticles until now. Clearly, the practical catalytic activities of such materials have hitherto been intrinsically restricted by the relatively small surface area and poor crystallinity of nanoparticles. Here, highly porous and “single-crystal-like” Mo2N nanobelts with high density of nanopores have been synthesized on gram-scale. These novel Mo2N nanobelts exhibited high electrocatalytic activity in alkaline electrolyte even better than that of other non-Pt materials and appear to be promising Pt-free cathodic electrocatalysts in alkaline fuel cells. This discovery reveals a new type of metal nitride ORR catalyst and appear to be promising Pt-free cathodic electrocatalysts in alkaline fuel cells.

•Graphene-like Co3O4 nanosheet/graphene hybrids have been successfully synthesized.•The Co3O4/graphene hybrids exhibit a very high reversible lithium storage capacity.•The Co3O4/graphene hybrids also exhibit an ultrahigh rate capability.We have successfully synthesized graphene-like Co(OH)2 and fabricated sandwich-like Co(OH)2/graphene hybrids by the electrostatic self-assembly. After annealing at low temperatures, we further fabricated Co3O4 nanosheet/graphene hybrids, in which the thickness of graphene-like Co3O4 nanosheets is only ∼5 nm. The as-prepared product exhibits a very high reversible lithium storage capacity up to 982.6 mAh g−1 after 50 cycles, while pure Co3O4 nanosheets only show the discharge capacity of 108 mAh g−1 after 50 cycles. Moreover, in comparison with the reported results, it exhibits an ultrahigh rate capability of 209.7 mAh g−1 at 5000 mA g−1. The greatly improved electrochemical performances may be ascribed to the sandwich-like structure of ultrathin Co3O4 nanosheet/graphene.

•Firstly applying porous Mo2N nanobelts in sodium ion batteries (NIBs).•Proved its good performance compared to the explored nitrides in NIBs.•Such material will be a new promising electrode active material for NIBs.The limited dynamics and poor cycling stabilities of the current reported anode materials have become the bottleneck for the practical applications and development of sodium-ion batteries (NIBs). It is very urgent to explore new anode materials for NIBs. Herein, we reported a new anode material for NIBs, molybdenum nitride (Mo2N). The synthesized Mo2N with porous nanobelt shape showed a “single-crystal-like” form of simple cubic crystal, and highly porous structure. Moreover, the Mo2N nanobelts exhibit an excellent capacity retention ratio of more than 85% after 200 cycles and fine rate performance. We believe that such porous Mo2N nanobelt will be a new promising electrode active material for NIBs.

•Na0.33V2O5@graphene composites were explored for sodium storage for the first time.•Na0.33V2O5@graphene composites with sandwich-like nanostructures were synthesized.•The composites exhibit excellent electrochemical performance as cathodes.Na0.33V2O5 nanosheet@graphene composites were explored as cathodes for sodium ion batteries for the first time. Here, Na0.33V2O5 nanosheet@graphene composites with special sandwich-like nanostructures were synthesized. The composites exhibit high discharge capacity (of ca. 213 mA h g−1 at 20 mA g−1), good cycling stability (with a capacity retention of 83.3% at 50 mA g−1 after 100 cycles) and desirable rate performance (88.2 mA h g−1 at an extremely high current density of 6000 mA g−1) as cathodes for sodium storage. Notably, the as-synthesized Na0.33V2O5 nanosheet@graphene composites show much higher specific capacity and better rate capability than those reported Na0.33V2O5 materials which were usually tested at relatively low currents (no more than 200 mA g−1) and showed low capacities (less than 150 mA h g−1).

According to recent reports, a multiphase design can provide a new method to improve the performance of L4T5O12–TiO2 anodes for lithium-ion batteries (LIBs). But in the case of sodium-ion batteries (SIBs), little attention is paid to the investigation of whether TiO2 phases have similar effects as they have in LIBs. In this paper, uniform pristine Li4Ti5O12 (LTO) and Li4Ti5O12–rutile TiO2 (LTO–RT) nanosheets were successfully fabricated on a large scale via a simple hydrothermal reaction. Their electrochemical performance as anodes for SIBs was carefully compared for the first time. The results show that the existence of TiO2 phases in LTO–TiO2 composites has a positive effect on the capacity but a negative effect on the cyclability as anodes for SIBs, which is very different from the previously reported effects of TiO2 phases in LTO–TiO2 composites as anodes for LIBs. Moreover, LTO nanosheets fabricated by our synthesis method deliver a reversible capacity up to 145 mA h g−1 at 1C and keep 91% capacity retention after 400 cycles. As far as we know, this is the longest cycle life to date for SIBs using LTO as anode materials. Based on a scan rate-dependent cyclic voltammetry test, a pseudocapacitive charge storage mechanism has been firstly proposed for Na-ion storage in a pristine LTO electrode, which contributes to the excellent rate capacity and such high cycling stability of LTO electrodes for SIBs.

Na0.33V2O5 nanosheet-graphene hybrids were successfully fabricated for the first time via a two-step route involving a novel hydrothermal method and a freeze-drying technique. Uniform Na0.33V2O5 nanosheets with a thickness of about 30 nm are well-dispersed between graphene layers. The special sandwich-like nanostructures endow the hybrids with high discharge capacity, good cycling stability, and superior rate performance as cathodes for lithium storage. Desirable discharge capacities of 313, 232, 159, and 108 mA·h·g–1 can be delivered at 0.3, 3, 6, and 9 A·g–1, respectively. Moreover, the Na0.33V2O5-graphene hybrids can maintain a high discharge capacity of 199 mA·h·g–1 after 400 cycles even at an extremely high current density of 4.5 A·g–1, with an average fading rate of 0.03% per cycle.Keywords: facile synthesis; high-rate performance; lithium ion batteries; Na0.33V2O5 nanosheet-graphene hybrids; sandwich-like nanostructures

•Lithium-containing ternary oxides Li3VO4 have been synthesized with “graphene-like” ultrathin nanoribbon stuctures and their thickness is about 3 nm.•We achieved the preparation of ultrathin Li3VO4 nanoribbon @ graphene nanosheets nanocomposite through a layer-by-layer assembly method. Such unique sandwich-like nanostructures showed ultrahigh lithium ion storage properties.•Such template strategy, using "graphene-like" binary inorganic nanosheets as templates to synthesize lithium-containing ternary oxide nanosheets, may be extended to prepare other ternary oxides with "graphene-like" nanostructures.Two-dimensional (2D) “graphene-like” inorganic materials, because of the short lithium ion diffusion path and unique 2D carrier pathways, become a new research focus of the lithium storages. Some “graphene-like” binary compounds, such as, MnO2, MoS2 and VO2 ultrathin nanosheets, have been synthesized by the peeling method, which also exhibit enhanced lithium storage performances. However, it still remains a great challenge to synthesize widely-used lithium-containing ternary oxides with “graphene-like” nanostructures, because the lithium-containing ternary oxides, unlike ternary layered double hydroxides (LDH), are very hard to be directly peeled. Herein, we successfully synthesized ultrathin Li3VO4 nanoribbons with a thickness of about 3 nm by transformation from ultrathin V2O5·xH2O nanoribbons, moreover, we achieved the preparation of ultrathin Li3VO4 nanoribbon@graphene sandwich-like nanostructures (LVO/G) through the layer-by-layer assembly method. The unique sandwich-like nanostructures shows not only a high specific reversible capacitance (up to 452.5 mA h g−1 after 200 cycles) but also an excellent cycling performance (with more than 299.2 mA h g−1 of the capacity at 10C after 1000 cycles) as well as very high rate capability. Such template strategy, using “graphene-like” binary inorganic nanosheets as templates to synthesize lithium-containing ternary oxide nanosheets, may be extended to prepare other ternary oxides with “graphene-like” nanostructures.

A facile and effective method has been reported to synthesize graphene-encapsulated α-MoO3 nanoribbons by a self-assembly process between negatively charged graphene oxide and positively charged MoO3 nanoribbons. Compared to the structures of MoO3 nanobelts grown on graphene or other hybrids of MoO3 composited with carbon or non-carbon, this unique hybrid architecture of the graphene-encapsulated MoO3 nanoribbons exhibits not only a high specific capacity (up to 823 mAh g−1 after 70 cycles at 200 mA g−1), but also an excellent cycling performance (with more than 754 mAh g−1 after 200 cycles at 1000 mA g−1 ) as well as a greatly-enhanced high-rate capability (displaying a high discharge capacity of 710 mAh g−1 after 30 cycles at 3000 mA g−1), thus showing great potential as an anode material for lithium ion batteries.

•We have successfully synthesized ultrafine MoO2 nanoparticles grown on graphene sheets through a facile hydrothermal process which only involves commercial MoO3, ethylene glycol and GO as starting materials.•More importantly, the ultrafine MoO2 nanoparticle/graphene hybrids show superior performances as an anode material for lithium ion batteries.•The as-formed MoO2/graphene product shows areversible lithium storage capacity as high as 765.3 mA h g-1after 40 cycles, as anode materials for lithium ion batteries.We have successfully synthesized ultrafine MoO2 nanoparticles with the diameter of ~5 nm grown on graphene sheets through a facile hydrothermal process which only involves commercial MoO3, ethylene glycol and GO as starting materials. More importantly, the ultrafine MoO2 nanoparticle/graphene hybrids exhibit great electrochemical performances with reversible lithium storage capacity as high as 765.3 mA h g−1 after 40 cycles, as anode materials for lithium ion batteries.

Multiwalled carbon nanotube (MWCNT)–vanadium pentoxide (V2O5) nanocomposites have been fabricated using a facile and environmental friendly hydrothermal method without any pretreatment, surfactants, or chelate agents added. The as-annealed nanocomposites are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), and the results indicate that V2O5 nanoparticles grew on MWCNTs. As a cathode material for lithium batteries, it exhibits superior electrochemical performance compare to the pure V2O5 powders. A high specific discharge capacity of 253 mA h g−1 can be obtained for the 15 % MWCNT–V2O5 nanocomposite electrodes, which retains 209 mA h g−1 after 50 cycles. However, the pure V2O5 powder electrodes only possess a specific discharge capacity of 157 mA h g−1 with a capacity retention of 127 mA h g−1 after 50 cycles. Moreover, the MWCNT–V2O5 nanocomposite electrodes show an excellent rate capability with a specific discharge capacity of 180 mA h g−1 at the current rate of 4 C. The enhanced electrochemical performance of the nanocomposites is attributed to the formation of conductive networks by MWCNTs, and large surface areas of V2O5 nanoparticles grew on MWCNTs which stabilizes these nanoparticles against agglomeration.

According to recent reports, a multiphase design can provide a new method to improve the performance of L4T5O12–TiO2 anodes for lithium-ion batteries (LIBs). But in the case of sodium-ion batteries (SIBs), little attention is paid to the investigation of whether TiO2 phases have similar effects as they have in LIBs. In this paper, uniform pristine Li4Ti5O12 (LTO) and Li4Ti5O12–rutile TiO2 (LTO–RT) nanosheets were successfully fabricated on a large scale via a simple hydrothermal reaction. Their electrochemical performance as anodes for SIBs was carefully compared for the first time. The results show that the existence of TiO2 phases in LTO–TiO2 composites has a positive effect on the capacity but a negative effect on the cyclability as anodes for SIBs, which is very different from the previously reported effects of TiO2 phases in LTO–TiO2 composites as anodes for LIBs. Moreover, LTO nanosheets fabricated by our synthesis method deliver a reversible capacity up to 145 mA h g−1 at 1C and keep 91% capacity retention after 400 cycles. As far as we know, this is the longest cycle life to date for SIBs using LTO as anode materials. Based on a scan rate-dependent cyclic voltammetry test, a pseudocapacitive charge storage mechanism has been firstly proposed for Na-ion storage in a pristine LTO electrode, which contributes to the excellent rate capacity and such high cycling stability of LTO electrodes for SIBs.

Flexible batteries have attracted much attention in recent years due to their promising applications in flexible displays, portable consumer electronic devices, and thin-film-based electronics. However, their practical applications are still limited by their low active material mass-loading in flexible electrodes and poor lithium storage performances. In this work, we have successfully grown highly crystalline VO2 nanobelt arrays on carbon fiber cloth (CFC) for the first time. The strategy only involves a facile one-pot solvothermal method. As binder-free flexible electrodes for LIBs, even with active material mass loading dramatically reaching up to 5.2 mg per square centimeter, such a novel CFC@VO2 (B) nanobelt array cathode electrode still exhibits a specific capacity of 145 mA h g−1 (90% of theoretical capacity), excellent cyclability with capacity retention over 90% after 200 cycles at ∼9C (1000 mA g−1), and high rate capability at high current densities up to ∼20C (2000 mA g−1). Such an excellent cathode material is very desirable in high-power flexible LIBs. The effective combination of CFC and a high areal mass loading of active materials described in this paper is a feasible and effective solution to design high-performance flexible batteries, especially high-power flexible batteries.