Disassembly–Reassembly Approach to RuO2/Graphene Composites for Ultrahigh Volumetric Capacitance Supercapacitor

A porous, yet compact, RuO₂/graphene hybrid is successfully prepared by using a disassembly–reassembly strategy, achieving effective and uniform loading of RuO₂ nanoparticles inside compact graphene monolith. The disassembly process ensures the uniform loading of RuO₂ nanoparticles into graphene monolith, while the reassembly process guarantees a high density yet simultaneously unimpeded ion transport channel in the composite. The resulting RuO₂/graphene hybrid possesses a density of 2.63 g cm⁻³, leading to a record high volumetric capacitance of 1485 F cm⁻³ at the current density of 0.1 A g⁻¹. When the current density is increased to 20 A g⁻¹, it remains a high volumetric capacitance of 1188 F cm⁻³. More importantly, when the single electrode mass loading is increased to 12 mg cm⁻², it still delivers a high volumetric capacitance of 1415 F cm⁻³ at the current density of 0.1 A g⁻¹, demonstrating the promise of this disassembly–reassembly approach to create high volumetric performance materials for energy storage applications.     

A Solid‐State Fibriform Supercapacitor Boosted by Host–Guest Hybridization between the Carbon Nanotube Scaffold and MXene Nanosheets

Fiber‐shaped supercapacitors with improved specific capacitance and high rate capability are a promising candidate as power supply for smart textiles. However, the synergistic interaction between conductive filaments and active nanomaterials remains a crucial challenge, especially when hydrothermal or electrochemical deposition is used to produce a core (fiber)–shell (active materials) fibrous structure. On the other hand, although 2D pseudocapacitive materials, e.g., Ti₃C₂T _x (MXene), have demonstrated high volumetric capacitance, high electrical conductivity, and hydrophilic characteristics, MXene‐based electrodes normally suffer from poor rate capability owing to the sheet restacking especially when the loading level is high and solid‐state gel is used as electrolyte. Herein, by hosting MXene nanosheets (Ti₃C₂T _x ) in the corridor of a scrolled carbon nanotube (CNT) scaffold, a MXene/CNT fiber with helical structure is successfully fabricated. These features offer open spaces for rapid ion diffusion and guarantee fast electron transport. The solid‐state supercapacitor based on such hybrid fibers with gel electrolyte coating exhibits a volumetric capacitance of 22.7 F cm⁻³ at 0.1 A cm⁻³ with capacitance retention of 84% at current density of 1.0 A cm⁻³ (19.1 F cm⁻³), improved volumetric energy density of 2.55 mWh cm⁻³ at the power density of 45.9 mW cm⁻³, and excellent mechanical robustness.     

Nitrogen‐Doped Carbon Encapsulated Mesoporous Vanadium Nitride Nanowires as Self‐Supported Electrodes for Flexible All‐Solid‐State Supercapacitors

Flexible 3D nanoarchitectures have received tremendous interest recently because of their potential applications in flexible/wearable energy storage devices. Herein, 3D intertwined nitrogen‐doped carbon encapsulated mesoporous vanadium nitride nanowires (MVN@NC NWs) are investigated as thin, lightweight, and self‐supported electrodes for flexible supercapacitors (SCs). The MVN NWs have abundant active sites accessible to charge storage, and the N‐doped carbon shell suppresses electrochemical dissolution of the inner MVN NWs in an alkaline electrolyte, leading to excellent capacitive properties. The flexible MVN@NC NWs film electrode delivers a high areal capacitance of 282 mF cm⁻² and exhibits excellent long‐term stability with 91.8% capacitance retention after 12 000 cycles in a KOH electrolyte. All‐solid‐state flexible SCs assembled by sandwiching two flexible MVN@NC NWs film electrodes with alkaline poly(vinyl alcohol) (PVA), sodium polyacrylate, and KOH gel electrolyte boast a high volumetric capacitance of 10.9 F cm⁻³, an energy density of 0.97 mWh cm⁻³, and a power density of 2.72 W cm⁻³ at a current density of 0.051 A cm⁻³ based on the entire cell. By virtue of the excellent mechanical flexibility, high capacitance, and large energy/power density, the self‐supported MVN@NC NWs paper‐like electrodes have large potential applications in portable and wearable flexible electronics.     

Dual Molecules Cooperatively Confined In-Between Edge-oxygen-rich Graphene Sheets as Ultrahigh Rate and Stable Electrodes for Supercapacitors

Noncovalent modification of carbon materials with redox-active organic molecules has been considered as an effective strategy to improve the electrochemical performance of supercapacitors. However, their low loading mass, slow electron transfer rate, and easy dissolution into the electrolyte greatly limit further practical applications. Herein, this work reports dual molecules (1,5-dihydroxyanthraquinone (DHAQ) and 2,6-diamino anthraquinone (DAQ)) cooperatively confined in-between edge-oxygen-rich graphene sheets as high-performance electrodes for supercapacitors. Cooperative electrostatic-interaction on the edge-oxygen sites and π–π interaction in-between graphene sheets lead to the increased loading mass and structural stability of dual molecules. Moreover, the electron tunneling paths constructed between edge-oxygen groups and dual molecules can effectively boost the electron transfer rate and redox reaction kinetics, especially at ultrahigh current densities. As a result, the as-obtained electrode exhibits a high capacitance of 507 F g⁻¹ at 0.5 A g⁻¹, and an unprecedented rate capability (203 F g⁻¹ at 200 A g⁻¹). Moreover, the assembled symmetrical supercapacitor achieves a high energy density of 17.1 Wh kg⁻¹ and an ultrahigh power density of 140 kW kg⁻¹, as well as remarkable stability with a retention of 86% after 50 000 cycles. This work may open a new avenue for the efficient utilization of organic materials in energy storage and conversion.     

An Ultrafast Conducting Polymer@MXene Positive Electrode with High Volumetric Capacitance for Advanced Asymmetric Supercapacitors

Pseudocapacitors or redox capacitors that synergize the merits of batteries and double‐layer capacitors are among the most promising candidates for high‐energy and high‐power energy storage applications. 2D transition metal carbides (MXenes), an emerging family of pseudocapacitive materials with ultrahigh rate capability and volumetric capacitance, have attracted much interest in recent years. However, MXenes have only been used as negative electrodes as they are easily oxidized at positive (anodic) potential. To construct a high‐performance MXene‐based asymmetric device, a positive electrode with a compatible performance is highly desired. Herein, an ultrafast polyaniline@MXene cathode prepared by casting a homogenous polyaniline layer onto a 3D porous Ti₃C₂T_x MXene is reported, which enables the stable operation of MXene at positive potentials because of the enlarged work function after compositing with polyaniline, according to the first‐principle calculations. The resulting flexible polyaniline@MXene positive electrode demonstrates a high volumetric capacitance of 1632 F cm^?3 and an ultrahigh rate capability with 827 F cm^?3 at 5000 mV s^?1, surpassing all reported positive electrodes. An asymmetric device is further fabricated with MXene as the anode and polyaniline@MXene as the cathode, which delivers a high energy density of 50.6 Wh L^?1 and an ultrahigh power density of 127 kW L^?1.     

Low-Temperature Resistant Stretchable Micro-Supercapacitor Based on 3D Printed Octet-Truss Design

Recently, stretchable micro-supercapacitors (MSCs) that can be easily integrated into electronic devices have attracted research and industrial attentions. In this work, three-dimensional (3D) stretchable MSCs with an octet-truss electrode (OTE) design have been demonstrated by a rapid digital light processing (DLP) process. The 3D-printed electrode structure is beneficial for electrode-electrolyte interface formation and consequently increases the number of ions adsorbed on the electrode surface. The designed MSCs can achieve a high capacitance as ≈74.76 mF cm⁻³ under 1 mA cm⁻³ at room temperature even under a high mechanical deformation, and can achieve 19.53 mF cm⁻³ under 0.1 mA cm⁻³ at a low temperature (−30 °C). Moreover, finite element analysis (FEA) reveals the OTE structure provides 8 times more contact area per unit volume at the electrode-electrolyte interface compared to the traditional interdigital electrode (IDE). This work combines structural design and 3D printing techniques, which provides new insights into highly stretchable MSCs for next-generation electronic devices.     

Ultra‐light Hierarchical Graphene Electrode for Binder‐Free Supercapacitors and Lithium‐Ion Battery Anodes

A mild and environmental‐friendly method is developed for fabricating a 3D interconnected graphene electrode with large‐scale continuity. Such material has interlayer pores between reduced graphene oxide nanosheets and in‐plane pores. Hence, a specific surface area up to 835 m² g⁻¹ and a high powder conductivity up to 400 S m⁻¹ are achieved. For electrochemical applications, the interlayer pores can serve as “ion‐buffering reservoirs” while in‐plane ones act as “channels” for shortening the mass cross‐plane diffusion length, reducing the ion response time, and prevent the interlayer restacking. As binder‐free supercapacitor electrode, it delivers a specific capacitance up to 169 F g⁻¹ with surface‐normalized capacitance close to 21 μF cm⁻² (intrinsic capacitance) and power density up to 7.5 kW kg⁻¹, in 6 m KOH aqueous electrolyte. In the case of lithium‐ion battery anode, it shows remarkable advantages in terms of the initiate reversible Coulombic efficiency (61.3%), high specific capacity (932 mAh g⁻¹ at 100 mA g⁻¹), and robust long‐term retention (93.5% after 600 cycles at 2000 mAh g⁻¹).     

Supercapacitor Electrodes Based on Hierarchical Mesoporous MnOx/Nitrided TiO2 Nanorod Arrays on Carbon Fiber Paper

Metal nitride nanoarrays are attractive to electrochemical energy storage and in this work, hierarchical mesoporous manganese oxide (MnO_x) nanoflakes and nitrided TiO₂ nanorod arrays (NTNA) are prepared on carbon fiber paper (CFP) by hydrothermal synthesis and electrodeposition. The MnO_x/NTNA/CFP electrode delivers outstanding electrochemical performance such as high areal capacitance of 327 mF cm⁻² at a current density of 0.25 mA cm⁻² and good cycling stability with 96% retention after 5000 cycles. Compared to the MnO_x/TiO₂/CFP and MnO_x/CFP electrodes, the MnO_x/NTNA/CFP electrode possesses better electrochemical properties such as higher areal capacitance, better electrochemical activity, and cycling life. The enhanced performance can be attributed to the nitrided TiO₂ nanorod arrays with higher conductivity offering low electrochemical impedance and fast ion/electron transfer. The MnO_x/NTNA/CFP electrode is a promising candidate in high‐performance supercapacitor applications.     

3D Printing of Freestanding MXene Architectures for Current‐Collector‐Free Supercapacitors

Additive manufacturing (AM) technologies appear as a paradigm for scalable manufacture of electrochemical energy storage (EES) devices, where complex 3D architectures are typically required but are hard to achieve using conventional techniques. The combination of these technologies and innovative material formulations that maximize surface area accessibility and ion transport within electrodes while minimizing space are of growing interest. Herein, aqueous inks composed of atomically thin (1–3 nm) 2D Ti₃C₂T_x with large lateral size of about 8 µm possessing ideal viscoelastic properties are formulated for extrusion‐based 3D printing of freestanding, high specific surface area architectures to determine the viability of manufacturing energy storage devices. The 3D‐printed device achieves a high areal capacitance of 2.1 F cm^?2 at 1.7 mA cm^?2 and a gravimetric capacitance of 242.5 F g^?1 at 0.2 A g^?1 with a retention of above 90% capacitance for 10 000 cycles. It also exhibits a high energy density of 0.0244 mWh cm^?2 and a power density of 0.64 mW cm^?2 at 4.3 mA cm^?2. It is anticipated that the sustainable printing and design approach developed in this work can be applied to fabricate high‐performance bespoke multiscale and multidimensional architectures of functional and structural materials for integrated devices in various applications.     

MOF‐Derived Hollow Cage NixCo3−xO4 and Their Synergy with Graphene for Outstanding Supercapacitors

Highly optimized nickel cobalt mixed oxide has been derived from zeolite imidazole frameworks. While the pure cobalt oxide gives only 178.7 F g^?1 as the specific capacitance at a current density of 1 A g^?1, the optimized Ni:Co 1:1 has given an extremely high and unprecedented specific capacitance of 1931 F g^?1 at a current density of 1 A g^?1, with a capacitance retention of 69.5% after 5000 cycles in a three electrode test. This optimized Ni:Co 1:1 mixed oxide is further used to make a composite of nickel cobalt mixed oxide/graphene 3D hydrogel for enhancing the electrochemical performance by virtue of a continuous and porous graphene conductive network. The electrode made from GNi:Co 1:1 successfully achieves an even higher specific capacitance of 2870.8 F g^?1 at 1 A g^?1 and also shows a significant improvement in the cyclic stability with 81% capacitance retention after 5000 cycles. An asymmetric supercapacitor is also assembled using a pure graphene 3D hydrogel as the negative electrode and the GNi:Co 1:1 as the positive electrode. With a potential window of 1.5 V and binder free electrodes, the capacitor gives a high specific energy density of 50.2 Wh kg^?1 at a high power density of 750 W kg^?1.     

The Structural and Electronic Engineering of Molybdenum Disulfide Nanosheets as Carbon-Free Sulfur Hosts for Boosting Energy Density and Cycling Life of Lithium–Sulfur Batteries

The compact sulfur cathodes with high sulfur content and high sulfur loading are crucial to promise high energy density of lithium–sulfur (Li–S) batteries. However, some daunting problems, such as low sulfur utilization efficiency, serious polysulfides shuttling, and poor rate performance, are usually accompanied during practical deployment. The sulfur hosts play key roles. Herein, the carbon-free sulfur host composed of vanadium-doped molybdenum disulfide (VMS) nanosheets is reported. Benefiting from the basal plane activation of molybdenum disulfide and structural advantage of VMS, high stacking density of sulfur cathode is allowed for high areal and volumetric capacities of the electrodes together with the effective suppression of polysulfides shuttling and the expedited redox kinetics of sulfur species during cycling. The resultant electrode with high sulfur content of 89 wt.% and high sulfur loading of 7.2 mg cm⁻² achieves high gravimetric capacity of 900.9 mAh g⁻¹, the areal capacity of 6.48 mAh cm⁻², and volumetric capacity of 940 mAh cm⁻³ at 0.5 C. The electrochemical performance can rival with the state-of-the-art those in the reported Li–S batteries. This work provides methodology guidance for the development of the cathode materials to achieve high-energy-density and long-life Li–S batteries.     

A TiN Nanorod Array 3D Hierarchical Composite Electrode for Ultrahigh‐Power‐Density Bromine‐Based Flow Batteries

Bromine‐based flow batteries are well suited for stationary energy storage due to attractive features of high energy density and low cost. However, the bromine‐based flow battery suffers from low power density and large materials consumption due to the relatively high polarization of the Br₂/Br^? couple on the electrodes. Herein, a self‐supporting 3D hierarchical composite electrode based on a TiN nanorod array is designed to improve the activity of the Br₂/Br^? couple and increase the power density of the bromine‐based flow battery. In this design, a carbon felt provides a composite electrode with a 3D electron conductive framework to guarantee high electronic conductivity, while the TiN nanorods possess excellent catalytic activity for the Br₂/Br^? electrochemical reaction to reduce the electrochemical polarization. Moreover, the 3D micro–nano hierarchical nanorod‐array alignment structure contributes to a high electrolyte penetration and a high ion‐transfer rate to reduce diffusion polarization. As a result, a zinc–bromine flow battery with the designed composite electrode can be operated at a current density of up to 160 mA cm^?2, which is the highest current density ever reported. These results exhibit a promising strategy to fabricate electrodes for ultrahigh‐power‐density bromine‐based flow batteries and accelerate the development of bromine‐based flow batteries.     

High Volumetric Energy Density Asymmetric Supercapacitors Based on Well‐Balanced Graphene and Graphene‐MnO2 Electrodes with Densely Stacked Architectures

The well‐matched electrochemical parameters of positive and negative electrodes, such as specific capacitance, rate performance, and cycling stability, are important for obtaining high‐performance asymmetric supercapacitors. Herein, a facile and cost‐effective strategy is demonstrated for the fabrication of 3D densely stacked graphene (DSG) and graphene‐MnO₂ (G‐MnO₂) architectures as the electrode materials for asymmetric supercapacitors (ASCs) by using MnO₂‐intercalated graphite oxide (GO‐MnO₂) as the precursor. DSG has a stacked graphene structure with continuous ion transport network in‐between the sheets, resulting in a high volumetric capacitance of 366 F cm^–3, almost 2.5 times than that of reduced graphene oxide, as well as long cycle life (93% capacitance retention after 10 000 cycles). More importantly, almost similar electrochemical properties, such as specific capacitance, rate performance, and cycling stability, are obtained for DSG as the negative electrode and G‐MnO₂ as the positive electrode. As a result, the assembled ASC delivers both ultrahigh gravimetric and volumetric energy densities of 62.4 Wh kg^–1 and 54.4 Wh L^–1 (based on total volume of two electrodes) in 1 m Na₂SO₄ aqueous electrolyte, respectively, much higher than most of previously reported ASCs in aqueous electrolytes.     

High-Performance Biodegradable Energy Storage Devices Enabled by Heterostructured MoO3–MoS2 Composites

Biodegradable implantable devices are of growing interest in biosensors and bioelectronics. One of the key unresolved challenges is the availability of power supply. To enable biodegradable energy-storage devices, herein, 2D heterostructured MoO₃–MoS₂ nanosheet arrays are synthesized on water-soluble Mo foil, showing a high areal capacitance of 164.38 mF cm⁻² (at 0.5 mA cm⁻²). Employing the MoO₃–MoS₂ composite as electrodes of a symmetric supercapacitor, an asymmetric Zn-ion hybrid supercapacitor, and an Mg primary battery are demonstrated. Benefiting from the advantages of MoO₃–MoS₂ heterostructure, the Zn-ion hybrid supercapacitors deliver a high areal capacitance (181.86 mF cm⁻² at 0.5 mA cm⁻²) and energy density (30.56 µWh cm⁻²), and the Mg primary batteries provide a stable high output voltage (≈1.6 V) and a long working life in air/liquid environment. All of the used materials exhibit desirable biocompatibility, and these fabricated devices are also fully biodegradable. Demonstration experiments display their potential applications as biodegradable power sources for various electronic devices.     

Atomic Interlamellar Ion Path in High Sulfur Content Lithium‐Montmorillonite Host Enables High‐Rate and Stable Lithium–Sulfur Battery

Fast lithium ion transport with a high current density is critical for thick sulfur cathodes, stemming mainly from the difficulties in creating effective lithium ion pathways in high sulfur content electrodes. To develop a high‐rate cathode for lithium–sulfur (Li–S) batteries, extenuation of the lithium ion diffusion barrier in thick electrodes is potentially straightforward. Here, a phyllosilicate material with a large interlamellar distance is demonstrated in high‐rate cathodes as high sulfur loading. The interlayer space (≈1.396 nm) incorporated into a low lithium ion diffusion barrier (0.155 eV) significantly facilitates lithium ion diffusion within the entire sulfur cathode, and gives rise to remarkable nearly sulfur loading‐independent cell performances. When combined with 80% sulfur contents, the electrodes achieve a high capacity of 865 mAh g^?1 at 1 mA cm^?2 and a retention of 345 mAh g^?1 at a high discharging/charging rate of 15 mA cm^?2, with a sulfur loading up to 4 mg. This strategy represents a major advance in high‐rate Li–S batteries via the construction of fast ions transfer paths toward real‐life applications, and contributes to the research community for the fundamental mechanism study of loading‐independent electrode systems.     

An Ultrahigh Output Rechargeable Electrode of a Hydrophilic Radical Polymer/Nanocarbon Hybrid with an Exceptionally Large Current Density beyond 1 A cm−2

Facile charge transport by a hydrophilic organic radical‐substituted polymer and the 3D current collection by a self‐assembled mesh of single‐walled carbon nanotube bundles lead to the operation of an ultrahigh‐output rechargeable electrode. Exceptionally large current density beyond 1 A cm^?2 and high areal capacity around 3 mAh cm^?2 are achieved, which are 10^1?2 times larger than those of the previously reported so‐called “ultrafast electrodes.” A sub‐millimeter‐thick, flexible, highly safe organic redox polymer‐based rechargeable device with an aqueous sodium chloride electrolyte is fabricated to demonstrate the superior performance.     

Tellurium: A High-Volumetric-Capacity Potassium-Ion Battery Electrode Material

Currently, exploring high-volumetric-capacity electrode materials that allow for reversible (de-)insertion of large-size K⁺ ions remains challenging. Tellurium (Te) is a promising alternative electrode for storage of K⁺ ions due to its high volumetric capacity, confirmed in lithium-/sodium-ion batteries, and the intrinsic good electronic conductivity. However, the charge storage capability and mechanism of Te in potassium-ion batteries (KIBs) have not been unveiled until now. Here, a novel K–Te battery is constructed, and the K⁺-ion storage mechanism of Te is revealed to be a two-electron conversion-type reaction of 2K + Te ↔ K₂Te, resulting in a high theoretical volumetric capacity of 2619 mAh cm⁻³. Consequently, the rationally fabricated tellurium/porous carbon electrodes deliver an ultrahigh reversible volumetric capacity of 2493.13 mAh cm⁻³ at 0.5 C (based on Te), a high-rate capacity of 783.13 mAh cm⁻³ at 15 C, and superior long-term cycling stability for 1000 cycles at 5 C. This excellent electrochemical performance proves the feasibility of utilizing Te as a high-volumetric-capacity active material for storage of K⁺ ions and will advance the practical application of KIBs.     

Vertically Aligned Graphene–Carbon Fiber Hybrid Electrodes with Superlong Cycling Stability for Flexible Supercapacitors

Graphene electrode–based supercapacitors are in high demand due to their superior electrochemical characteristics. A major bottleneck of using the supercapacitors for commercial applications lies in their inferior electrode cycle life. Herein, a simple and facile method to fabricate highly efficient supercapacitor electrodes using pristine graphene sheets vertically stacked and electrically connected to the carbon fibers which can result in vertically aligned graphene–carbon fiber nanostructure is developed. The vertically aligned graphene–carbon fiber electrode prepared by electrophoretic deposition possesses a mesoporous 3D architecture which enabled faster and efficient electrolyte‐ion diffusion with a gravimetric capacitance of 333.3 F g^?1 and an areal capacitance of 166 mF cm^?2. The electrodes displayed superlong electrochemical cycling stability of more than 100 000 cycles with 100% capacitance retention hence promising for long‐lasting supercapacitors. Apart from the electrochemical double layer charge storage, the oxygen‐containing surface moieties and α‐Ni(OH)₂ present on the graphene sheets enhance the charge storage by faradaic reactions. This enables the assembled device to provide an excellent gravimetric energy density of 76 W h kg^?1 with a 100% capacitance retention even after 1000 bending cycles. This study opens the door for developing high‐performing flexible graphene electrodes for wearable energy storage applications.     

Microcrack Arrays in Dense Graphene Films for Fast-Ion-Diffusion Supercapacitors

Laminated graphene film has great potential in compact high-power capacitive energy storage owing to the high bulk density and opened architecture. However, the high-power capability is usually limited by tortuous cross-layer ion diffusion. Herein, microcrack arrays are fabricated in graphene films as fast ion diffusion channels, converting tortuous diffusion into straightforward diffusion while maintaining a high bulk density of 0.92 g cm⁻³. Films with optimized microcrack arrays exhibit sixfold improved ion diffusion coefficient and high volumetric capacitance of 221 F cm⁻³ (240 F g⁻¹), representing a critical breakthrough in optimizing ion diffusion toward compact energy storage. This microcrack design is also efficient for signal filtering. Microcracked graphene-based supercapacitor with 30 µg cm⁻² mass loading exhibits characteristic frequency up to 200 Hz with voltage window up to 4 V, showing high promise for compact, high-capacitance alternating current (AC) filtering. Moreover, a renewable energy system is conducted using microcrack-arrayed graphene supercapacitors as filter-capacitor and energy buffer, filtering and storing the 50 Hz AC electricity from a wind generator into the constant direct current, stably powering 74 LEDs, demonstrating enormous potential in practical applications. More importantly, this microcracking approach is roll-to-roll producible, which is cost-effective and highly promising for large-scale manufacture.     

Roll-Pressed Silicon Anodes with High Reversible Volumetric Capacity Achieved by Interfacial Stabilization and Mechanical Strengthening of a Silicon/Graphene Hybrid Assembly

Application of Si anodes is hindered by severe capacity fading due to pulverization of Si particles during the large volume changes of Si during charge/discharge and repeated formation of the solid-electrolyte interphase. To address these issues, considerable efforts have been devoted to the development of Si composites with conductive carbons (Si/C composites). However, Si/C composites with high C content inevitably show low volumetric capacity because of low electrode density. For practical applications, the volumetric capacity of a Si/C composite electrode is more important than gravimetric capacity, but volumetric capacity in pressed electrodes is rarely reported. Herein, a novel synthesis strategy is demonstrate for a compact Si nanoparticle/graphene microspherical assembly with interfacial stability and mechanical strength achieved by consecutively formed chemical bonds using 3-aminopropyltriethoxysilane and sucrose. The unpressed electrode (density: 0.71 g cm⁻³) shows a reversible specific capacity of 1470 mAh g⁻¹ with a high initial coulombic efficiency of 83.7% at a current density of 1 C-rate. The corresponding pressed electrode (density: 1.32 g cm⁻³) exhibits high reversible volumetric capacity of 1405 mAh cm⁻³ and gravimetric capacity of 1520 mAh g⁻¹ with a high initial coulombic efficiency of 80.4% and excellent cycling stability of 83% over 100 cycles at 1 C-rate.