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Tin‐based hybrid flow batteries have demonstrated dendrite‐free morphology and superior performance in terms of cycle life and energy density. However, the quick accumulation of electrodeposits near the electrode/membrane interface blocks the ion transport pathway during the charging of the battery, resulting to a very limited areal capacity (especially at high current density) that significantly hinders its deployment in long‐duration storage applications. Herein, a conductivity‐activity dual‐gradient design is disclosed by electrically passivating the carbon felt near the membrane/electrode interface and chemically activating the carbon felt near the electrode/current collector interface. In consequence, the tin metals are preferentially plated at the region near electrode/current collector, preventing the ion transport pathway from being easily blocked. The resultant gradient electrode demonstrated an unprecedentedly high areal capacity of 268 mAh cm−2 at a current density of as high as 80 mA cm−2. Numerical modeling and experimental characterizations show that the dual‐gradient electrode differs from conventional electrodes with regard to their reaction current density distribution and electrodeposit distribution during charging. This work demonstrates a new design strategy of 3D electrodes for hybrid flow batteries to induce a desirable distribution of electrodeposits and achieve a high areal capacity at commercially relevant current densities. [ABSTRACT FROM AUTHOR]

The accelerated oxidative degradation observed in all‐solid‐state batteries (ASSBs), particularly focusing on the argyrodite solid electrolyte in conjunction with Ni‐rich positive electrode surfaces is demonstrated. The formation of oxidative intermediates of the solid electrolyte oxidation process increases the amount of oxidation on the NCM surface with conductive carbon. The introduction of high‐weight‐composition conductive carbon additives results in a reduction of solid electrolytes within the positive electrode and the amount of solid electrolytes retained after formation. Consequently, cells with high concentrations of carbon additives demonstrate a decrease in both the cycle and power performances of ASSBs. The energy density of ASSBs is significantly limited by the fundamental failure mechanism induced by conductive carbon, particularly pronounced in cells with high active material contents. Consequently, this study provides pivotal insights for the design of high‐energy‐density ASSBs with NCM electrodes and high active material contents. To mitigate failure induced by high‐volumetric‐occupied carbon additives, carbon fiber‐type additives are further utilized to interconnect the NCMs by decreasing the occupation of the solid electrolyte domain by carbon. Morphological alteration of the carbon additive significantly improves the electrochemical performance of ASSBs by preventing the deterioration of the electrode structure even after prolonged cycling and suppressing electrolyte degradation. [ABSTRACT FROM AUTHOR]

Aqueous rechargeable zinc‐sulfur (Zn‐S) batteries are a promising, cost‐effective, and high‐capacity energy storage technology. Still, they are challenged by the poor reversibility of S cathodes, sluggish redox kinetics, low S utilization, and unsatisfactory areal capacity. This work develops a facile strategy to achieve an appealing high‐areal‐capacity (above 5 mAh cm−2) Zn‐S battery by molecular‐level regulation between S and high‐electrical‐conductivity tellurium (Te). The incorporation of Te as a dopant allows for manipulation of the Zn‐S electrochemistry, resulting in accelerated redox conversion, and enhanced S utilization. Meanwhile, accompanied by the S‐ZnS conversion, Te is converted to zinc telluride during the discharge process, as revealed by ex‐situ characterizations. This additional redox reaction contributes to the S cathode's total excellent discharge capacity. With this unique cathode structure design, the carbon‐confined TeS cathode (denoted as Te1S7/C) delivers a high reversible capacity of 1335.0 mAh g−1 at 0.1 A g−1 with a mass loading of 4.22 mg cm−2, corresponding to a remarkable areal capacity of 5.64 mAh cm−2. Notably, a hybrid electrolyte design uplifts discharge plateau, reduces overpotential, suppresses Zn dendrites growth, and extends the calendar life of Zn‐Te1S7 batteries. This study provides a rational S cathode structure to realize high‐capacity Zn‐S batteries for practical applications. [ABSTRACT FROM AUTHOR]

The development of low‐cost and high‐performance iron (Fe)‐based anode materials is of great significance for rechargeable aqueous batteries. Herein, a FeS@Fe foam anode with crosslinked nanoflake array structure is fabricated. Being adopted as alkaline anode, FeS@Fe foam delivers enhanced areal capacity of 31.1 mAh cm−2 (at 50 mA cm−2), which is ≈1.5 times that of the‐state‐of‐the‐art literatures. The scaled‐up tests further reveal the higher capacity (800.7 mAh) and current density (1.25 A) with the area of 25 cm2. The FeS@Fe foam anode sustains intact after 270‐day cycles, demonstrating excellent durability. The assembled FeS//NiO single battery provides a superior areal energy density of 300.7 Wh m−2 at 500 W m−2. The reaction mechanism and electrode kinetics are revealed by combining in/ex situ techniques and DFT calculations. Experimental results and in/ex situ characterizations validate that excellent structural stability and high areal capacity are attributed to effective interface regulation and improved energy storage mechanism, respectively. This work pushes the advanced Fe‐based electrode to a superior level among these available alkaline solid‐state batteries. [ABSTRACT FROM AUTHOR]

Nanostructured silicon anodes have shown extraordinary lithium storage properties for lithium-ion batteries (LIBs) but are usually achieved at low areal loadings (< 1.5 mg·cm−2) with low areal capacity. Sustaining sound electrochemical performance at high loading requires proportionally higher ion/electron currents and robust structural stability in the thicker electrode. Herein, we report a three-dimensional (3D) printed silicon-graphene-carbon nanotube (3D-Si/G/C) electrode for simultaneously achieving ultrahigh areal/gravimetric capacities at high mass loading. The periodically arranged vertical channels and hierarchically porous filaments facilitate sufficient electrolyte infiltration and rapid ion diffusion, and the carbonaceous network provides excellent electron transport properties and mechanical integrity, thus endowing the printed 3D-Si/G/C electrode with fast electrochemical reaction kinetics and reversibility at high mass loading. Consequently, the 3D-Si/G/C with high areal mass loading of 12.9 mg·cm−2 exhibits excellent areal capacity of 12.8 mAh·cm−2 and specific capacity of 1007 mAh·g−1, respectively. In-situ optical microscope and ex-situ scanning electron microscope (SEM) confirm that the hierarchically porous filaments with interconnected carbon skeletons effectively suppress the volume change of silicon and maintain stable micro-lattice architecture. A 3D printed 3D-Si/G/C-1∥3D-LiFePO4/G full cell holds excellent cyclic stability (capacity retention rate of 78% after 50 cycles) with an initial Coulombic efficiency (ICE) of 96%. This work validates the feasibility of 3D printing on constructing high mass loading silicon anode for practical high energy-density LIBs. [ABSTRACT FROM AUTHOR]

The addition of zinc can induce the formation of polymetallic (Zn-Ni-Co) carbonate hydroxides/hydroxides (MCHs/M(OH) 2) heterostructure nanosheet array with rich defect structures on Ni foam as a superior cathode (ZNC/NF) for alkaline aqueous rechargeable Zn-based batteries (AAZBs). The as-made binder-free cathode offers an extremely high mass loading of 9.2 mg cm−2, exhibiting excellent areal capacities and energy densities. [Display omitted] Developing high mass loading cathodes with high capacity and durable life cycles is greatly worthwhile and challenging for alkaline aqueous rechargeable Zn-based batteries (AAZBs). Herein, we demonstrate an efficient zinc-induced strategy to rationally develop Zn-Ni-Co carbonate hydroxides/hydroxides heterostructure nanosheet array with an extremely high mass loading of 9.2 mg cm−2 on Ni foam (ZNC/NF) as such a superior cathode for AAZBs. It is discovered that Ni-Co hydroxide nanowires can be transformed into Zn-Ni-Co carbonate hydroxides/hydroxides heterostructure nanosheet with rich defect structures after the introduction of Zn during the synthetic process. The formed heterostructures and rich defect structures can enhance ion and electron transfer efficiency, thus ensuring the excellent electrochemical performance under high loading condition. Consequently, the ZNC/NF//Zn battery shows an outstanding areal capacity of 2.1 mAh cm−2 at 5 mA cm−2, with an ultrahigh energy density of 3.6 mWh cm−2. Moreover, the battery can still retain a high capacity of 0.42 mAh cm−2 after 5000 cycles at 50 mA cm−2, suggesting strong long-term cycling stability. This research enables pave the way for the rational design and manufacture of advanced electrode materials with large mass loadings. [ABSTRACT FROM AUTHOR]

Ensuring a stable power output from renewable energy sources, such as wind and solar energy, depends on the development of large-scale and long-duration energy storage devices. Zinc–bromine flow batteries (ZBFBs) have emerged as cost-effective and high-energy-density solutions, replacing expensive all-vanadium flow batteries. However, uneven Zn deposition during charging results in the formation of problematic Zn dendrites, leading to mass transport polarization and self-discharge. Stable Zn plating and stripping are essential for the successful operation of high-areal-capacity ZBFBs. In this study, we successfully synthesized nitrogen and oxygen co-doped functional carbon felt (NOCF4) electrode through the oxidative polymerization of dopamine, followed by calcination under ambient conditions. The NOCF4 electrode effectively facilitates efficient "shuttle deposition" of Zn during charging, significantly enhancing the areal capacity of the electrode. Remarkably, ZBFBs utilizing NOCF4 as the anode material exhibited stable cycling performance for 40 cycles (approximately 240 h) at an areal capacity of 60 mA h/cm2. Even at a high areal capacity of 130 mA h/cm2, an impressive energy efficiency of 76.98% was achieved. These findings provide a promising pathway for the development of high-areal-capacity ZBFBs for advanced energy storage systems. [ABSTRACT FROM AUTHOR]

Abstract Aqueous rechargeable zinc‐sulfur (Zn‐S) batteries are a promising, cost‐effective, and high‐capacity energy storage technology. Still, they are challenged by the poor reversibility of S cathodes, sluggish redox kinetics, low S utilization, and unsatisfactory areal capacity. This work develops a facile strategy to achieve an appealing high‐areal‐capacity (above 5 mAh cm−2) Zn‐S battery by molecular‐level regulation between S and high‐electrical‐conductivity tellurium (Te). The incorporation of Te as a dopant allows for manipulation of the Zn‐S electrochemistry, resulting in accelerated redox conversion, and enhanced S utilization. Meanwhile, accompanied by the S‐ZnS conversion, Te is converted to zinc telluride during the discharge process, as revealed by ex‐situ characterizations. This additional redox reaction contributes to the S cathode's total excellent discharge capacity. With this unique cathode structure design, the carbon‐confined TeS cathode (denoted as Te1S7/C) delivers a high reversible capacity of 1335.0 mAh g−1 at 0.1 A g−1 with a mass loading of 4.22 mg cm−2, corresponding to a remarkable areal capacity of 5.64 mAh cm−2. Notably, a hybrid electrolyte design uplifts discharge plateau, reduces overpotential, suppresses Zn dendrites growth, and extends the calendar life of Zn‐Te1S7 batteries. This study provides a rational S cathode structure to realize high‐capacity Zn‐S batteries for practical applications.

Designing ultrathick and hierarchical electrodes is effective to deal with the challenge of high areal capacity and high power density for lithium-ion batteries (LIBs) manufacturing. Here, a thick electrode with hierarchical porous and multidimensional conductive network is fabricated by 3D printing technology, in which both the conducting polymer of poly(3,4-ethylene dioxythiophene):polystyrene sulfonate (PEDOT:PSS) and graphene oxide (GO) play the dual roles as binders and conductive agents. As a consequence, the 3D-printed thick electrode (∼900 μm) with a mass loading of ∼47 mg/cm2 exhibits a good rate capability of 122 mA·h/g at 2 C, a high areal capacity of up to 5.8 mA·h/cm2, and stable cycling performance of ∼95% capacity retention after 100 cycles. Moreover, the C-O-S bond is further confirmed by the spectral analysis and the DFT calculation, which not only hinders the stack of nanosheets but enhances the mechanical stability and electronic conductivity of electrodes. A stable covalent multidimensional conductive network constructed by 3D-printing technology provides a new design strategy to improve the performance of LIBs.

Highlights This study introduces an innovative 3D-printed electrolyte with vertically aligned ion transport network, which contains well-dispersed nanoscale Ta-doped Li7La3Zr2O12 in a poly(ethylene glycol) diacrylate matrix. The 3DSE architecture enables efficient ion transport across the Li/electrolyte and electrolyte/cathode interfaces, which allows for increased active material mass loading and enhanced interfacial adhesion. The p-3DSE Li symmetric cell displays an impressive critical current density value of 1.92 mA cm−2 and stable operation for 2600 h at room temperature. Full cells using p-3DSE achieve notable areal capacities.

The design of supercapacitor materials with both high mass loading and high areal capacity is a major strategy to overcome relatively low energy density of supercapacitors. Herein, NiCo‐layered double hydroxide (NiCo‐LDH)/NiCoOOH composite films with both ultrahigh mass loading and high areal capacity are prepared by a two‐step cyclic voltammetry method. The films consist of NiCo‐LDH/NiCoOOH microspheres assembled with ultrafine nanosheets with highly ordered pore distribution from macropores to micropores and abundant defect active sites, which are conducive to the transport of electrolyte ions, increasing the reaction kinetics, and greatly improving the utilization of active material. The optimal film with hierarchical microstructure featuring an ultrahigh mass loading of 80 mg cm−2 not only exhibits a state‐of‐the‐art high areal capacity of 14.7 mAh cm−2, but also shows a record‐high energy density of 10.7 mWh cm−2 , as well as presents remarkable mechanical stabilityand superior capacity retention of 99% after 20000 galvanostatic charge‐discharge cycles. Moreover, by combining the experimental analysis and theoretical calculations, the mechanism of preferential conversion of the NiCo‐LDH in the subtle defect region to NiCoOOH by electrochemistry and the synergistic effect in electrochemical energy storage of the NiCo‐LDH and NiCoOOH phases is proposed. [ABSTRACT FROM AUTHOR]

Ultra-thick, dense alloy-type anodes are promising for achieving large areal and volumetric performance in potassium-ion batteries (PIBs), but severe volume expansion as well as sluggish ion and electron diffusion kinetics heavily impede their widespread application. Herein, we design highly dense (3.1 ​g ​cm−3) Ti3C2Tx MXene and graphene dual-encapsulated nano-Sb monolith architectures (HD-Sb@Ti3C2Tx-G) with high-conductivity elastic networks (1560 ​S ​m−1) and compact dually encapsulated structures, which exhibit a large volumetric capacity of 1780.2 ​mAh cm−3 (gravimetric capacity: 565.0 ​mAh g−1), a long-term stable lifespan of 500 cycles with 82% retention, and a large areal capacity of 8.6 ​mAh cm−2 (loading: 31 ​mg ​cm−2) in PIBs. Using ex-situ SEM, in-situ TEM, kinetic investigations, and theoretical calculations, we reveal that the excellent areal and volumetric performance mechanism stems from the three dimensional (3D) high-conductivity elastic networks and the dual-encapsulated Sb architecture of Ti3C2Tx and graphene; these effectively mitigate against volume expansion and the pulverization of Sb, offering good electrolyte penetration and rapid ionic/electronic transmission. Ti3C2Tx also decreases the K+ diffusion energy barrier, and the ultra-thick compact electrode ensures volumetric and areal performance. These findings provide a feasible strategy for fabricating ultra-thick, dense alloy-type electrodes to achieve high areal and volumetric capacity energy storage via highly-dense, dual-encapsulated architectures with conductive elastic networks.

Higher-energy-density, Wh L−1 or Wh kg−1, lithium-ion cells are one of the critical advancements required for the implementation of electric vehicles. This increase leads to a longer drive distance between recharges. Aside from material development, full lithium-ion cell design parameters have the potential to greatly influence fabricated cell energy density. The following work highlights the impact of these full-cell design parameters, investigating the effect of a negative to positive capacity ratio, positive electrode porosity, positive electrode active material content, and overall charge voltage on stack volumetric energy density. Decreasing the N:P ratio or increasing active material content results in an almost identical volumetric energy density increase: ~4%. Decreasing the positive electrode porosity from 40–30% or increasing the charge voltage from 4.2–4.35 V also results in an almost identical increase in volumetric energy density: ~5.5%. Combining all design changes has the potential to increase stack volumetric energy density by 20% compared to the baseline cell design. [ABSTRACT FROM AUTHOR]

[Display omitted] Silicon (Si) is considered as one of the most promising candidates for next-generation lithium-ion battery (LIB) anode due to its high theoretical capacity. However, the drastic volume change of Si anodes during lithiation/delithiation processes leads to rapid capacity fade. Herein, a three-dimensional Si anode with multiple protection strategy is proposed, including citric acid-modification of Si particles (CA@Si), GaInSn ternary liquid metal (LM) addition, and porous copper foam (CF) based electrode. The CA modified supports strong adhesive attraction of Si particles with binder and LM penetration maintains good electrical contact of the composite. The CF substrate constructs a stable hierarchical conductive framework, which could accommodate the volume expansion to retain integrity of the electrode during cycling. As a result, the obtained Si composite anode (CF-LM-CA@Si) demonstrates a discharge capacity of 3.14 mAh cm−2 after 100 cycles at 0.4 A g−1, corresponding to 76.1% capacity retention rate based on the initial discharge capacity and delivers comparable performance in full cells. The present study provides an applicable prototype of high-energy density electrodes for LIBs. [ABSTRACT FROM AUTHOR]

Lithium sulfur batteries are suitable for drones due to their high gravimetric energy density (2600 Wh/kg of sulfur). However, on the cathode side, high specific capacity with high sulfur loading (high areal capacity) is challenging due to the poor conductivity of sulfur. Shuttling of Li-sulfide species between the sulfur cathode and lithium anode also limits specific capacity. Sulfur-carbon composite active materials with encapsulated sulfur address both issues but require expensive processing and have low sulfur content with limited areal capacity. Proper encapsulation of sulfur in carbonaceous structures along with active additives in solution may largely mitigate shuttling, resulting in cells with improved energy density at relatively low cost. Here, composite current collectors, selected binders, and carbonaceous matrices impregnated with an active mass were used to award stable sulfur cathodes with high areal specific capacity. All three components are necessary to reach a high sulfur loading of 3.8 mg/cm2 with a specific/areal capacity of 805 mAh/g/2.2 mAh/cm2. Good adhesion between the carbon-coated Al foil current collectors and the composite sulfur impregnated carbon matrices is mandatory for stable electrodes. Swelling of the binders influenced cycling retention as electroconductivity dominated the cycling performance of the Li-S cells comprising cathodes with high sulfur loading. Composite electrodes based on carbonaceous matrices in which sulfur is impregnated at high specific loading and non-swelling binders that maintain the integrated structure of the composite electrodes are important for strong performance. This basic design can be mass produced and optimized to yield practical devices. [ABSTRACT FROM AUTHOR]

Improving the energy density of Li-ion batteries is critical to meet the requirements of electric vehicles and energy storage systems. In this work, LiFePO4 active material was combined with single-walled carbon nanotubes as the conductive additive to develop high-energy-density cathodes for rechargeable Li-ion batteries. The effect of the morphology of the active material particles on the cathodes' electrochemical characteristics was investigated. Although providing higher packing density of electrodes, spherical LiFePO4 microparticles had poorer contact with an aluminum current collector and showed lower rate capability than plate-shaped LiFePO4 nanoparticles. A carbon-coated current collector helped enhance the interfacial contact with spherical LiFePO4 particles and was instrumental in combining high electrode packing density (1.8 g cm−3) with excellent rate capability (100 mAh g−1 at 10C). The weight percentages of carbon nanotubes and polyvinylidene fluoride binder in the electrodes were optimized for electrical conductivity, rate capability, adhesion strength, and cyclic stability. The electrodes that were formulated with 0.25 wt.% of carbon nanotubes and 1.75 wt.% of the binder demonstrated the best overall performance. The optimized electrode composition was used to formulate thick free-standing electrodes with high energy and power densities, achieving the areal capacity of 5.9 mAh cm−2 at 1C rate. [ABSTRACT FROM AUTHOR]

The development of sodium ion batteries will require high‐performance electrodes with very large areal capacity and reasonable rate performance. Although red phosphorus is a very promising electrode material, it has not yet fulfilled these requirements. Here, liquid phase exfoliation is used to convert solid red phosphorus into amorphous, quasi‐2D nanoplatelets. These nanoplatelets have lateral sizes of hundreds of nanometers, thickness of 10s of nanometers and are quite stable in ambient conditions, displaying only low levels of oxidation on the nanosheet surface. By solution mixing with carbon nanotubes, these nanoplatelets can be fabricated into nanocomposite battery anodes. After employing an extended activation process, good cycling stability over 1000 cycles and low‐rate capacitances >2000 mAh gP−1 is achieved. Because of the high conductivity and mechanical robustness provided by the nanotube network, it is possible to fabricate very thick electrodes. These electrodes display extremely high areal capacities approaching 10 mAh cm−2 at currents of ≈1 mA cm−2. Detailed analysis shows these electrodes to be limited by solid‐state diffusion such that the thickest electrodes have state‐of‐the‐art rate performance and a near‐optimized combination of capacity and rate performance. [ABSTRACT FROM AUTHOR]

High mass loading and high areal capacity are essential for lithium‐ion batteries (LIBs) with high energy density, but they usually suffer from the sluggish charge‐transfer kinetic of thick electrodes, especially at low temperature. Here, organic molecule perylene‐3,4,9,10‐tetracarboxylic dianhydride (PTCDA) has been investigated as a feasible cathode for high areal capacity rechargeable LIBs operated at low temperature. Specifically, the charge storage process mainly occurs on the surface redox‐active groups of PTCDA, resulting in a fast kinetics of charge storage. Meanwhile, the delocalization of electrons in the π‐conjugated systems of PTCDA could enhance the electron transportation prominently. Consequently, the Li‐PTCDA battery with a high mass loading of 14.35 mg cm−2 delivers a high reversible areal capacity of 1.06 mAh cm−2 at −40 °C. This work demonstrates a great potential of π‐conjugated organic materials for low temperature and high‐areal‐capacity rechargeable LIBs. [ABSTRACT FROM AUTHOR]

In recent decades, extensive nanomaterials and related techniques have been proposed to achieve high capacities surpassing conventional battery electrodes. Nevertheless, most of them show low mass loadings and areal capacities, which deteriorates the cell‐level energy densities and increases cost after the consideration of inactive components in batteries. Achieving high‐areal‐capacity is essential for those advanced materials to move out of laboratories and into practical applications, yet remains challenging due to the decreased mechanical properties and sluggish electrochemical kinetics at elevated mass loadings. In this paper, the previously reported strategies for promoting areal lithium storage performance, including material‐level designs, electrode‐level architecture optimization, and novel manufacturing techniques are reviewed. Sodium‐ion battery electrodes are discussed subsequently, emphatically on its difference with those for lithium storage. Pouch‐cell‐level energy densities based on high‐areal‐capacity electrodes with different thicknesses are also estimated. For each category of these strategies, working principles, advantages, and possible problems are analyzed, with typical examples presented in detail and a summary table comparing the structures and achieved performance. Finally, the features of the high‐areal‐capacity electrodes demonstrated in this review are concluded, and overlooked issues and potential research directions in this field are summarized. [ABSTRACT FROM AUTHOR]

[Display omitted] The fast development of flexible devices has greatly boosted the demands for flexible lithium-ion batteries (LIBs). Accordingly, a broad exploration of flexible electrodes in LIBs is crucial. At present, the major challenge in the flexible electrode for lithium-ion batteries (LIBs) is how to achieve an excellent electrochemical performance (particularly high-energy density) while maintaining superior mechanical flexibility. Herein, flexible silicon/carbon nanotube (Si/CNT) electrode is prepared via a common blade-coating, which is adoptable to large-scale production. The CNT network from monodispersed CNT solution endows the electrode with superior tensile strength and mechanical toughness. The tensile strength of the flexible electrodes is up to 3.75 MPa, and the corresponding strain at break is 43.9%. The flexible electrode delivers an areal capacity of 10.6 mAh cm−2 at 0.06 mA cm−2, which is completely meet the practical requirement (1–3 mAh cm−2). And a high reversible capacity of 5.64 mAh cm−2 can be retained at 0.3 mA cm−2 after 200 cycles. In addition, the pouch cell exhibits a promising cycling stability under the repeated deformation state. Moreover, this work also provides a feasible and scalable method to fabricate flexible electrodes for other wearable energy storage systems. [ABSTRACT FROM AUTHOR]

Wearable power supply devices and systems are important necessities for the emerging textile electronic applications. Current energy supply devices usually need more space than the device they power, and are often based on rigid and bulky materials, making them difficult to wear. Fabric-based batteries without any rigid electrical components are therefore ideal candidates to solve the problem of powering these devices. Printing technologies have greater potential in manufacturing lightweight and low-cost batteries with high areal capacity and generating high voltages which are crucial for electronic textile (e-textile) applications. In this review, we present various printing techniques, and battery chemistries applied for smart fabrics, and give a comparison between them in terms of their potential to power the next generation of electronic textiles. Series combinations of many of these printed and distributed battery cells, using electrically conducting threads, have demonstrated their ability to power different electronic devices with a specific voltage and current requirements. Therefore, the present review summarizes the chemistries and material components of several flexible and textile-based batteries, and provides an outlook for the future development of fabric-based printed batteries for wearable and electronic textile applications with enhanced level of DC voltage and current for long periods of time.

Higher-energy-density, Wh L−1 or Wh kg−1, lithium-ion cells are one of the critical advancements required for the implementation of electric vehicles. This increase leads to a longer drive distance between recharges. Aside from material development, full lithium-ion cell design parameters have the potential to greatly influence fabricated cell energy density. The following work highlights the impact of these full-cell design parameters, investigating the effect of a negative to positive capacity ratio, positive electrode porosity, positive electrode active material content, and overall charge voltage on stack volumetric energy density. Decreasing the N:P ratio or increasing active material content results in an almost identical volumetric energy density increase: ~4%. Decreasing the positive electrode porosity from 40–30% or increasing the charge voltage from 4.2–4.35 V also results in an almost identical increase in volumetric energy density: ~5.5%. Combining all design changes has the potential to increase stack volumetric energy density by 20% compared to the baseline cell design.

We report the fabrication of nanocystalline MnO 2 thin film-based electrode on a predeposited indium tin oxide (ITO) film on the glass substrate, using a binderless and simple two-electrode electrofabrication approach. Effects of Co and Cu incorporation on microstructural and electrochemical performance of the electrode were optimally and extensively investigated. The experimental results for the optimum fabrication conditions for Co@MnO 2 and Cu@MnO 2 and pure MnO 2 thin film-based electrode samples showed uniqueness in microstructural features, degrees of crystallinity and roughness, and high electrochemical energy storage performance. Co@MnO 2 film electrode exhibited remarkable specific capacitance (1068 Fg-1) and areal capacity (25.78 mAh cm−2) as against other electrode films (Cu@MnO 2 and pure MnO 2) which exhibited specific capacitances 837 and 438 F g−1 and areal capacities 10.6 and 4.9 mAh cm−2, respectively. Exceptional stabilities were also recorded for the composite samples (87.2% and 84.4% for Cu@MnO 2 and Co@MnO 2 thin film electrodes, respectively) against the pure MnO 2 film electrode sample (77.8%), after 2000 cycles. In addition, the short time constants (1.27 s and 1.31 s) were respectively realized for the fabricated Co@MnO 2 and Cu@MnO 2 electrode films as against the pure MnO 2 electrodes (4.35 s). These features observed in the composite electrode samples demonstrated an exhibition of faster ion response and higher rate capability by the samples. Moreover, the incorporation of Co into the MnO 2 electrode material relatively improved the supercapacitive activeness by enhancing the charge transition and transport. [ABSTRACT FROM AUTHOR]

The practical application of rechargeable aqueous zinc batteries is impeded by dendrite growth, especially at high areal capacities and high current densities. Here, this challenge is addressed by proposing zinc perfluoro(2‐ethoxyethane)sulfonic (Zn(PES)2) as a zinc battery electrolyte. This new amphipathic zinc salt, with a hydrophobic perfluorinated tail, can form an anode protecting layer, in situ, with a biomimetic lipid‐bilayer structure. The layer limits the anode contact with free H2O and offers fast Zn2+ transport pathways, thereby effectively suppressing dendrite growth while maintaining high rate capability. A stable, Zn2+‐conductive fluorinated solid electrolyte interphase (SEI) is also formed, further enhancing zinc reversibility. The electrolyte enables unprecedented cycling stability with dendrite‐free zinc plating/stripping over 1600 h at 1 mA cm−2 at 2 mAh cm−2, and over 380 h under an even harsher condition of 2.5 mA cm−2 and 5 mAh cm−2. Full cell tests with a high‐loading VS2 cathode demonstrate good capacity retention of 78% after 1000 cycles at 1.5 mA cm−2. The idea of in situ formation of a biomimetic lipid‐bilayer anode protecting layer and fluorinated SEI opens a new route for engineering the electrode–electrolyte interface toward next‐generation aqueous zinc batteries with long lifetime and high areal capacities. [ABSTRACT FROM AUTHOR]

Freestanding nanofiber mat Li-ion battery anodes containing Si nanoparticles, carbon black, and poly(acrylic acid) (Si/C/PAA) are prepared using electrospinning. The mats are compacted to a high fiber volume fraction (≈0.85), and interfiber contacts are welded by exposing the mat to methanol vapor. A compacted+welded fiber mat anode containing 40 wt % Si exhibits high capacities of 1484 mA h g-1 (3500 mA h g-1Si ) at 0.1 C and 489 mA h g-1 at 1 C and good cycling stability (e.g., 73 % capacity retention over 50 cycles). Post-mortem analysis of the fiber mats shows that the overall electrode structure is preserved during cycling. Whereas many nanostructured Si anodes are hindered by their low active material loadings and densities, thick, densely packed Si/C/PAA fiber mat anodes reported here have high areal and volumetric capacities (e.g., 4.5 mA h cm-2 and 750 mA h cm-3 , respectively). A full cell containing an electrospun Si/C/PAA anode and electrospun LiCoO2 -based cathode has a high specific energy density of 270 Wh kg-1 . The excellent performance of the electrospun Si/C/PAA fiber mat anodes is attributed to the: i) PAA binder, which interacts with the SiOx surface of Si nanoparticles and ii) high material loading, high fiber volume fraction, and welded interfiber contacts of the electrospun mats.

Lithium sulfur batteries are suitable for drones due to their high gravimetric energy density (2600 Wh/kg of sulfur). However, on the cathode side, high specific capacity with high sulfur loading (high areal capacity) is challenging due to the poor conductivity of sulfur. Shuttling of Li-sulfide species between the sulfur cathode and lithium anode also limits specific capacity. Sulfur-carbon composite active materials with encapsulated sulfur address both issues but require expensive processing and have low sulfur content with limited areal capacity. Proper encapsulation of sulfur in carbonaceous structures along with active additives in solution may largely mitigate shuttling, resulting in cells with improved energy density at relatively low cost. Here, composite current collectors, selected binders, and carbonaceous matrices impregnated with an active mass were used to award stable sulfur cathodes with high areal specific capacity. All three components are necessary to reach a high sulfur loading of 3.8 mg/cm2 with a specific/areal capacity of 805 mAh/g/2.2 mAh/cm2. Good adhesion between the carbon-coated Al foil current collectors and the composite sulfur impregnated carbon matrices is mandatory for stable electrodes. Swelling of the binders influenced cycling retention as electroconductivity dominated the cycling performance of the Li-S cells comprising cathodes with high sulfur loading. Composite electrodes based on carbonaceous matrices in which sulfur is impregnated at high specific loading and non-swelling binders that maintain the integrated structure of the composite electrodes are important for strong performance. This basic design can be mass produced and optimized to yield practical devices.

[Display omitted] • Crystalline/amorphous Co 2 P 2 O 7 was prepared in situ on nickel foam through hydrothermal and CVD annealing process. • The CP-P-450//Zn battery achieves an extraordinary areal capacity of 2.49 mAh/cm2 at a current density of 5 mA/cm2. • The CP-P-450//Zn battery showed superior areal energy densities (4.16 mWh/cm2) and peak power densities (115.94 mW/cm2). • The cycling durability of CP-P-450//Zn battery reached to 96.6% after 4000 cycles. It is still a challenge to develop aqueous rechargeable Zn-based alkaline batteries with high energy density, power density and excellent stability. Herein, a crystalline/amorphous Co 2 P 2 O 7 self-supporting on the Ni foam is fabricated as a cathode material of aqueous Zn-based alkaline batteries. The unique crystalline/amorphous structure endows the electrode material with more exposed active sites, higher redox species coverage, larger electrochemical surface area (ECSA), smaller charge-transfer resistance, lower reaction energy barriers and faster electrochemical reaction kinetics process, which clarifies an explicit structure–property relationship simultaneously. As a result, the crystalline/amorphous Co 2 P 2 O 7 (CP-P-450) electrode assembled as CP-P-450//Zn battery achieves an extraordinary areal capacity of 2.49 mAh cm−2 at 5 mA cm−2, satisfactory rate performance, excellent cyclic durability (96.6 % retention after 4000 cycles) and impressive energy density (4.16 mAh cm−2) and peak power density (115.94 mW cm−2). The quasi-solid CP-P-450//Zn battery can drive a variety of electrical appliances working well even under abuse tests, demonstrating excellent safety and application potential. This study provides an effective strategy towards excellent comprehensive energy storage performance of aqueous Zn-based alkaline batteries through structuring the crystalline/amorphous phase in cathodes. [ABSTRACT FROM AUTHOR]

Although numerous methods have been widely used to prepare nickel hydroxide materials, there is still a demand for lowering the required heating time, temperature, and cost with maintaining a high-quality nanomaterial for electrochemical energy storage. In this research, we study the relationship between microwave-assisted heating parameters and material properties of nickel hydroxide nanoflakes and evaluate their effect on electrochemical performance. X-ray diffraction spectra show that the samples prepared at the highest temperature of 220 °C have crystallized in the beta phase of nickel hydroxide crystal. While the sample synthesized at 150 °C in 30 min contains both beta and alpha phases. Interestingly, we obtained the pure alpha phase at 150 °C in just 10 min. A scanning electron microscope shows that increasing the temperature and heating time leads to enlarging the diameter of the macro-porous flower-like clusters of interconnected nanoflakes. Electrochemical measurements in potassium hydroxide electrolytes demonstrate that the alpha phase's electrodes have much higher capacities than samples containing only the beta phase. The maximum areal capacity of 17.7 µAh/cm2 and gravimetric capacity of 35.4 mAh/g are achieved, respectively, at 0.2 mA/cm2 and 0.4 A/g, with a small equivalent series resistance value of 0.887 ohms on flexible stainless-steel mesh as a current collector. These improved nickel hydroxide electrodes can be ascribed to utilizing the diffusion-controlled redox reactions that are detected up to the high scan of 100 mV/s. Such fast charge-discharge processes expand the range of potential applications. Our nickel hydroxide electrode, with its rapid preparation at medium temperature, can be a cost-effective candidate for flexible supercapacitors and batteries. [ABSTRACT FROM AUTHOR]

In existing dynamic spectrum sharing (DSS) systems, each node arbitrates channel access independently based on carrier-sensing mechanisms such as the listen-before-talk (LBT) protocol. Owing to the uncoordinated channel access between all nodes, the channel is occupied in a random pattern. This makes it difficult to reduce the mismatch in channel quality indicator (CQI) while increasing the spatial reuse gain between the different nodes; therefore, the areal capacity gain obtained by adding nodes is much lower in existing DSS systems than in the cellular system. In this paper, we propose a different means of improving the areal capacity for downlink DSS systems. It is a group-wise DSS approach that ensures full frequency reuse in each group of base stations (BSs) by performing LBT only between the representative BSs, each of them selected by each group. Once a channel is secured by each group, all its member BSs share a channel simultaneously. This approach makes closed-loop feedback-based link adaptation practical while boosting spatial reuse gain even in the DSS environment. To implement the group-wise DSS, we propose a single unified framework that employs elementary algorithms for BS grouping and carrier-sensing threshold adjustment. Our system-level simulation results demonstrate that the proposed framework boosts the areal capacity gain by approximately 4.42 times as much as the conventional approach.

Lithium-ion micro-batteries (LIMBs) with higher energy density have drawn extensive attention. 3D printing technique based on direct ink writing (DIW) is a low-cost and simple approach to fabricate LIMBs especially with higher areal capacity. Herein, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) nanofibrils are first combined with carbon methyl cellulose (CMC) to achieve the 3D printing of thick LFP (LiFePO4)-PEDOT-CMC electrodes at room temperature by DIW. 3D-printed PEDOT-CMC-based composite thick electrodes demonstrate high conductivity because of the interconnected 3D network including hierarchical macro-micro porous criss-crossing filaments which can provide effective transport paths for Li ions and electrons. Further, LFP-PEDOT-CMC electrodes of different thicknesses are 3D-printed to study the effect of thicknesses on the electrochemical performances. The 3D-printed ultra-thick LFP-CMC-PEDOT electrode of 1.43 mm thickness at lower rate exhibits a highly improved areal capacity (5.63 mAh cm−2, 0.2 C) and high capacity retention (after 100 cycles, 0.2 C, 92%). The rate capability decreases steadily with the increasing thickness. However, for the extra-thick electrodes greater than 1.43 mm thickness, the discharge capacity, rate, and cycle capability decline dramatically. Electrochemical impedance spectroscopy measurements are used to explain the kinetic mechanism. For 3D-printed LFP-CMC-PEDOT electrodes blow 1.43 mm thickness, the 3D network plays the dominant role to maintain the effective transmission dynamics regardless of electrode thickness. But for the extra-thick electrodes, the greater transport distance becomes the major limiting factor resulting in the degradation of electrochemical performances. This work will offer guidance on how to apply 3D-printed ultra-thick electrodes with high energy density to LIMBs. [ABSTRACT FROM AUTHOR]

The commercialization of lithium-sulfur (Li-S) battery could be accelerated by designing advanced sulfur cathode with high sulfur utilization and stable cycle life at a high sulfur loading. To allow the energy density of Li-S batteries comparable to that of commercial Li-ion batteries, the areal capacity of sulfur cathode should be above 4 mA·h·cm−2. In general, a high sulfur loading often causes rapid capacity fading by slowing electron/ion transport kinetics, catastrophic shuttle effect and even cracking the electrodes. To address this issue, herein, a multilevel structured carbon film is built by covering highly conductive CNTs and hollow carbon nanofiber together with carbon layer via chemical vapor deposition. The self-standing carbon film exhibits well-interweaved conductive network, hollow fibrous structure and abundant N, O co-doped active sites, which combine the merits of high electronic conductivity (1200·S·m−1), high porosity and polar characteristic in one host. Benefiting from this attractive multilevel structure, the obtained sulfur cathode based on the carbon film host shows an ultra-high areal capacity of 8.9 mA·h·cm−2 at 0.2 C with outstanding cyclability over 60 cycles. This work shed light on designing advanced sulfur host for Li-S batteries with high areal capacity and high cycle stability, and might make a contribution to the commercialization of Li-S batteries. [ABSTRACT FROM AUTHOR]

The electrode materials are traditionally loaded on the surface of the metal current collector by using of roll coating methods in sodium-ion batteries (SIBs). However, with the increase of the mass loading, the sodium storage performance of the cathodes deteriorates dramatically in the traditional casting process. In this work, we propose a novel strategy by applying electrospinning and airbrush-spraying technique to fabricate Na0.44MnO2-based paper (NMO-BP) electrodes. The results indicate that the NMO-BP electrodes show good electrochemical performance in terms of high areal capacities and good cycling stability with the loaded Na0.44MnO2 active material increasing from 2.6 to 10.4 mg cm−2. A high areal capacities of 1.10 mAh cm−2 is obtained in the NMO-BP electrodes with high areal loading (> 10 mg cm−2) for SIBs. This research provides a new method to explore cathode materials for sodium-ion battery with higher areal capacities. [ABSTRACT FROM AUTHOR]

Herein, we successfully deposit V2O5 nanobelt arrays on Ni foam uniformly coated with reduced graphene oxides (rGO), to manufacture V2O5/rGO arrays directly as anode for SIBs. The ordered and open architecture of V2O5/rGO arrays greatly facilitates the transportation of sodium ions and electrons. In particular, the introduction of rGO can substantially advance the whole electronic conductivity of the V2O5/rGO anode, as well as efficaciously prevent the V2O5 arrays exfoliation from the substrate. Consequently, the electrochemical performance of V2O5/rGO arrays can be highly improved compared with bare V2O5 arrays. As expected, the V2O5/rGO arrays anode yields a reversible capacity of 0.62 mAh cm−2 after 100 cycles at 0.4 mA cm−2 in the potential range of 0.01–3 V. It can be predicted that this innovative trial in this article might pave the way for tailoring high performance V2O5-based anode materials. [ABSTRACT FROM AUTHOR]

The fabrication, by an electrochemical process, of a new battery‐type electrode material, is presented. Such materials are fabricated by direct current electrodeposition of Ni(OH)2 on lamellar Ni3Si. Microstructure and morphology of Ni(OH)2/Ni3Si electrodes were characterised. Cyclic voltammetry and galvanostatic charge–discharge results revealed that they are battery‐type electrodes. Increasing deposition time or decreasing discharge current can significantly increase the areal capacity. The areal capacity of Ni(OH)2/Ni3Si‐20 with a discharge current of 20 mA is only 2.8% of that with 1 mA. However, the increasing deposition time will reduce the cyclic stability of the electrodes. The initial areal capacity of Ni(OH)2/Ni3Si‐20 is twice that of Ni(OH)2/Ni3Si‐10 with a discharge current of 10 mA, but after 1000 cycles, it can only maintain 59.3% of the initial value. This Letter is expected to provide a powerful reference and guidance for the preparation of electrodes with large areal capacity and cycle stability. [ABSTRACT FROM AUTHOR]

High areal capacity electrodes are essential to practical energy storage devices to achieve high volumetric capacity with compacted size. However, high loading of active materials remains a fundamental challenge for most metal‐ion batteries (e.g., Li+, Na+, K+) due to sluggish mass transfer kinetics and poor processability. Here, an ultrahigh areal capacity MoO3 electrode based on high loading for hydrogen‐ion battery is shown. Hydrogen ions can rapidly intercalate/deintercalate into/from MoO3‐nanofibers anode with a high specific capacity of 235 mAh g−1 at 5 C and superior rate capability up to 200 C at a low loading (≈1 mg cm−2). Attributed to the ultrafast H+ diffusion in thick MoO3 electrode, an areal capacity of 22.4 mAh cm−2 is achieved at the loading over 90.48 mg cm−2, which is the highest areal capacity ever reported for electrodes of rechargeable batteries, to the best of the authors' knowledge. This study paves the way toward high areal capacity batteries with high‐loading active materials. [ABSTRACT FROM AUTHOR]

High areal capacity electrodes are essential to practical energy storage devices to achieve high volumetric capacity with compacted size. However, high loading of active materials remains a fundamental challenge for most metal‐ion batteries (e.g., Li+, Na+, K+) due to sluggish mass transfer kinetics and poor processability. Here, an ultrahigh areal capacity MoO3 electrode based on high loading for hydrogen‐ion battery is shown. Hydrogen ions can rapidly intercalate/deintercalate into/from MoO3‐nanofibers anode with a high specific capacity of 235 mAh g−1 at 5 C and superior rate capability up to 200 C at a low loading (≈1 mg cm−2). Attributed to the ultrafast H+ diffusion in thick MoO3 electrode, an areal capacity of 22.4 mAh cm−2 is achieved at the loading over 90.48 mg cm−2, which is the highest areal capacity ever reported for electrodes of rechargeable batteries, to the best of the authors' knowledge. This study paves the way toward high areal capacity batteries with high‐loading active materials. [ABSTRACT FROM AUTHOR]

Silicon nanowires (Si NWs) have been identified as an excellent candidate material for the replacement of graphite in anodes, allowing for a significant boost in the capacity of lithium‐ion batteries (LIBs). Herein, high‐density Si NWs are grown on a novel 3D interconnected network of binary‐phase Cu‐silicide nanofoam (3D CuxSiy NF) substrate. The nanofoam facilitates the uniform distribution of well‐segregated and small‐sized catalyst seeds, leading to high‐density/single‐phase Si NW growth with an areal‐loading in excess of 1.0 mg cm−2 and a stable areal capacity of ≈2.0 mAh cm−2 after 550 cycles. The use of the 3D CuxSiy NF as a substrate is further extended for Al, Bi, Cu, In, Mn, Ni, Sb, Sn, and Zn mediated Si NW growth, demonstrating the general applicability of the anode architecture. [ABSTRACT FROM AUTHOR]

Silicon has been considered as a promising anode material for lithium‐ion batteries owing to its extraordinarily high capacity. However, the huge volume expansion during cycling results in severe pulverization and disintegration of active materials, especially when the particle size is in microscale. This challenge can be addressed by highly stretchable polymer binders engineered with helical polysaccharides. The elaborately designed binder presents excellent stretchability and adhesive property, which can buffer the strain caused by the large volume change and coalesce the pulverized silicon fragments without disintegration. As a result, the microsized silicon electrode exhibits high initial Coulombic efficiency of 91.8 % and excellent cycling stability for 300 cycles. Importantly, when paired with a commercial LiCoO2 cathode, the full cell manifests a high areal capacity of 3.02 mAh cm−2 and superior stability for 100 cycles. Our contribution paves the way to the practical application of microsized silicon for lithium‐ion batteries. [ABSTRACT FROM AUTHOR]

Niobium pentoxide (Nb 2 O 5) has attracted great attention as an anode for lithium-ion battery, which is attributed to the high-rate and good stability performances. In this work, TT-, T-, M-, and H-Nb 2 O 5 microspheres were synthesized by a facile one-step thermal oxidation method. Ion and electron transport properties of Nb 2 O 5 with different phases were investigated by both electrochemical analyses and density functional theoretical calculations. Without nanostructuring and carbon modification, the tetragonal Nb 2 O 5 (M-Nb 2 O 5) displays preferable rate capability (121 mAh g−1 at 5 A g−1), enhanced reversible capacity (163 mAh g−1 at 0.2 A g−1) and better cycling stability (82.3% capacity retention after 1000 cycles) when compared with TT-, T-, and H-Nb 2 O 5. Electrochemical analyses further reveal the diffusion-controlled Li+ intercalation kinetics and in-situ X-ray diffraction analysis indicates superior structural stability upon Li+ intercalation/deintercalation. Benefiting from the intrinsic fast ion/electron transport, a high areal capacity of 2.24 mAh cm−2 is obtained even at an ultrahigh mass loading of 22.51 mg cm−2. This work can promote the development of Nb 2 O 5 materials for high areal capacity and stable lithium storage towards practical applications. [ABSTRACT FROM AUTHOR]

It remains a great challenge to simultaneously guarantee the conductivity and high areal loading of active materials for integrated electrode of supercapacitors. Herein, we designed a hierarchical structure with cores of NiSe single‐crystal nanorods and sheaths of 2‐nm‐thick NiCo thin sheets grown on nickel foam (NiCo LDH@NiSe/NF) as integrated electrode. It reaches a high areal capacity of 1131 μAh cm−2 at a current density of 5 mA cm−2, which is 2.2 times of NiSe/NF (522 μAh cm−2) and 6.0 times of NiCo LDH/NF (189 μAh cm−2), superior to most reported integrated electrodes. The enhanced areal capacity can be ascribed to the high active material loading of 6.5 mg cm−2 (twice more than other reported values) and considerable conductivity of single‐crystal NiSe nanorods of 2630 S cm−1. The fabricated hierarchical integrated electrode of NiCo LDH@NiSe/NF assembled with activated carbon shows a maximum energy density of 0.454 mWh cm−2 and a maximum power density of 80 mW cm−2. This work presents supports of single‐crystal nanorods for thin LDH sheets to fabricate high‐density hierarchical structure for integrated electrode, which improves the conductivity and structural stability of active materials especially the LDHs, resulting in excellent electrochemical performance. It offers a promising approach to engineer and fabricate advanced supercapacitors with enhanced areal capacity. [ABSTRACT FROM AUTHOR]

Monolithic 3D graphene frameworks (GFs) electrode materials have exhibited the great potential for energy storage devices. However, most approaches for fabricating 3D GF require expensive and sophisticated drying techniques, and the current achieved 3D GF electrodes usually hold a relatively low mass loadings of the active materials with low areal capacity, which is not satisfactory for practical application. Herein, a convenient, economic, and scalable drying approach is developed to fabricate 3D holey GFs (HGFs) by a vacuum‐induced drying (VID) process for the first time. This binder‐free 3D HGF electrode with high mass loading can obtain extraordinary electrochemical performance for lithium‐ion batteries (LIBs) due to the 3D holey graphene network owning a highly interconnected hierarchical porous structure for fast charge and ion transport. The HGF electrode with high mass loading of 4 mg cm−2 exhibits superior rate performance and delivers an areal capacity as high as 5 mAh cm−2 under the current density of 8 mA cm−2 even after 2000 cycles, considerably outperforming those of state‐of‐the‐art commercial anodes and some representative anodes in other studies. This facile drying approach and robust realization of high areal capacity represent a critical step for 3D graphene‐based electrode materials toward practical electrochemical energy storage devices. [ABSTRACT FROM AUTHOR]

Hard carbons are perceived as promising anode materials in sodium-ion batteries, while their practical implementation is largely impeded by the insufficient initial Coulombic efficiency (ICE). Hard carbons with self-supporting architecture are intriguing to enhance ICE owing to the omission of binder and conductive agent; whereas elaborate architecture and microstructure design are still required to further raise the ICE to the level of commercial graphite in lithium-ion batteries, especially under high areal capacity. Herein, we propose a graphite-assisted pressurization strategy during carbonization to achieve remarkable ICE and high areal capacity in resulting self-supporting cellulose tissue derived hard carbon anode. The intimate contact of graphite plate enables suitable local ordering of pseudo-graphitic nanodomains with low intrinsic defects, responsible for enhanced ICE. While the pressure-reinforced dense yet self-interwoven fibrous networks render high areal capacity. Consequently, the as-prepared self-supporting hard carbon anode displays remarkable ICE to 95% and areal capacity of 2.4 mAh cm−2, far exceeding the reported value of less than 0.8 mAh cm−2. Meanwhile, the rate and durability are not scarified under such superior ICE due to the well-manipulated pseudo-graphitic nanodomains and porous fibrous networks. The practicality is further demonstrated in coin-type and pouch-type full cells delivering high capacity and long-term stability. Our finding offers an impetus for the development of high ICE and areal capacity for sodium-ion battery anode. [Display omitted] [ABSTRACT FROM AUTHOR]

Seawater batteries (SWBs) have attracted considerable attention as next-generation batteries owing to their high theoretical energy density and low cost. However, the practical energy density of SWBs is lower than that of conventional sodium-ion batteries as they contain a solid electrolyte with thickness limitations and inflexible mechanical properties. Considering the structure of SWBs, an increase in the anode thickness is required; however, the conventional high-mass-loading approaches are constrained by electrochemical and physical characteristics such as sluggish ion diffusion and delamination. In this study, we report the vertical arrangement of a conventional electrode to overcome the structural instability of the thick electrode and enable facile ion and electron transport by generating a vertically arranged electrode structure (VAES), which is verified using 3 different factors namely, vertical thickness, electrode compactness, and vertical angle. The electrode structures applied to the SWB anode exhibit a specific capacity of approximately 220 mAh/g over 100 cycles, achieving a high areal capacity of 75 mAh/cm2 in the coin cell, which is 50 times higher than that of a single-sheet electrode. This study demonstrates an efficient strategy to increase the energy density of SWB and provides valuable insights into the electrochemical characteristics of vertical electrode systems. [Display omitted] • Utilization of Vertically arranged Electrode structures with Seawater battery (SWB). • Evaluate 3 factors: Vertical thickness, electrode compactness and vertical angle. • Provide future direction of high energy density SWB and membrane battery systems. [ABSTRACT FROM AUTHOR]

Self-supported electrodes represent a novel architecture for better performing lithium ion batteries. However, lower areal capacity restricts their commercial application. Here, we explore a facial strategy to increase the areal capacity without sacrificing the lithium storage performance. A hierarchical CuO–Ge hybrid film electrode will not only provide high areal capacity but also outstanding lithium storage performance for lithium ion battery anode. Benefiting from the favorable structural advance as well as the synergic effect of the Ge film and CuO NWs array, the hybrid electrode exhibits a high areal capacity up to 3.81 mA h cm−2, good cycling stability (a capacity retention of 90.5% after 150 cycles), and superior rate performance (77.4% capacity remains even when the current density increased to 10 times higher).