Facile synthesis of free-standing silicon membranes with three-dimensional nanoarchitecture for anodes of lithium ion batteries

Bamboo Weaving Inspired Design of a Carbonaceous Electrode with Exceptionally High Volumetric Capacity

A highly densified electrode material is desirable to achieve large volumetric capacity. However, pores acting as ion transport channels are critical for high utilization of active material. Achieving a balance between high volume density and pore utilization remains a challenge particularly for hollow materials. Herein, capillary force is employed to convert hollow fibers to a bamboo-weaving-like flexible electrode (BWFE), in which the shrinkage of hollow space results in high compactness of the electrode. The volume of the electrode can be decreased by 96% without sacrificing the gravimetric capacity. Importantly, the conductivity of BWFE after thermal treatment can reach up to 50,500 S/m which exceeds that for most other carbon materials. Detailed mechanical analysis reveals that, due to the strong interaction between nanoribbons, Young's modulus of the electrode increases by 105 times. After SnO₂ active materials is impregnated, the BWFE/SnO₂ electrode exhibits an exceptionally ultrahigh volumetric capacity of 2000 mAh/cm³.

Enhanced Electrochemical Performance and Safety of Silicon by a Negative Thermal Expansion Material of ZrW2O8

Silicon (Si) faces big challenges in serious volume changes for applications in spite of its high theoretical capacity. Herein, a novel and facile method was proposed to decrease the volume change by simultaneously in situ absorbing the generated heat of only Si using a negative thermal expansion (NTE) material of ZrW₂O₈. The Si modified with 2 wt % of ZrW₂O₈ exhibits excellent structural integrity, electrochemical performance, and safety under various conditions, especially at elevated temperatures. Its reversible capacities can remain 1187.2 mA h g^-1 after 50 cycles and 643.8 mA h g^-1 after 100 cycles at 2 A g^-1 (∼199 and ∼190% higher than that of Si, respectively) at 25 °C. In addition, 930.6 mA h g^-1 is maintained after 50 cycles at 60 °C (∼219% higher than that of Si). As current densities increase to 2 and 4 A g^-1, the values still remain 1389.4 and 757.5 mA h g^-1, respectively, much higher than that of Si. Furthermore, the strain of Si is reduced by 37.2% using ZrW₂O₈ at 60 °C. Various products were analyzed, and the possible enhanced mechanism was discussed using multiple techniques. These findings exhibit significant potential for the improvement of energy materials using NTE materials by combining thermal effects and volume changes as well as the improved interface behavior.

Porous Si/Cu Anode with High Initial Coulombic Efficiency and Volumetric Capacity by Comprehensive Utilization of Laser Additive Manufacturing-Chemical Dealloying

Si has been extensively investigated as an anode material for lithium-ion batteries because of its superior theoretical capacity. However, a scalable fabrication method for a Si-based anode with high initial coulombic efficiency (ICE) and large volumetric capacity remains a critical challenge. Herein, we proposed a novel porous Si/Cu anode in which planar Si islands were embedded in the porous Cu matrix through combined laser additive manufacturing and chemical dealloying. The compositions and dimensions of the structure were controlled by metallurgical and chemical reactions during comprehensive interaction. Such a structure has the advantages of micro-sized Si and porous architecture. The planar Si islands decreased the surface area and thus increased ICE. The porous Cu matrix, which acted as both an adhesive-free binder and a conductive network, provided enough access for electrolyte and accommodated volume expansion. The anode structure was well maintained without observable mechanical damage after cycling, demonstrating the high structure stability and integrity. The porous Si/Cu anode showed a high ICE of 93.4% and an initial volumetric capacity of 2131 mAh cm^-3, which retained 1697 mAh cm^-3 after 100 cycles at 0.20 mA cm^-2. Furthermore, the full-cell configuration (porous Si/Cu //LiFePO₄) exhibited a high energy density of 464.9 Wh kg^-1 and a capacity retention of 84.2% after 100 cycles.

Tin-graphene tubes as anodes for lithium-ion batteries with high volumetric and gravimetric energy densities

Limited by the size of microelectronics, as well as the space of electrical vehicles, there are tremendous demands for lithium-ion batteries with high volumetric energy densities. Current lithium-ion batteries, however, adopt graphite-based anodes with low tap density and gravimetric capacity, resulting in poor volumetric performance metric. Here, by encapsulating nanoparticles of metallic tin in mechanically robust graphene tubes, we show tin anodes with high volumetric and gravimetric capacities, high rate performance, and long cycling life. Pairing with a commercial cathode material LiNi_0.6Mn_0.2Co_0.2O₂, full cells exhibit a gravimetric and volumetric energy density of 590 W h Kg⁻¹ and 1,252 W h L⁻¹, respectively, the latter of which doubles that of the cell based on graphite anodes. This work provides an effective route towards lithium-ion batteries with high energy density for a broad range of applications.

Here the authors report a tin anode design by encapsulating tin nanoparticles in graphene tubes. The design exhibits high capacity, good rate performance and cycling stability. Pairing with NMC, the full cell delivers a volumetric energy density twice as high as that for the commercial cell.

Heightened Integration of POM-based Metal-Organic Frameworks with Functionalized Single-Walled Carbon Nanotubes for Superior Energy Storage

To increase the conductivity of polyoxometalate-based metal-organic frameworks (POMOFs) and promote their applications in the field of energy storage, herein, a simple approach was employed to improve their overall electrochemical performances by introducing a functionalized single-walled carbon nanotubes (SWNT-COOH). A new POMOF compound, [Cu₁₈ (trz)₁₂ Cl₃ (H₂ O)₂ ][PW₁₂ O₄₀ ] (CuPW), was successfully synthesized, then the size-matched functionalized SWNT-COOH was introduced to fabricate CuPW/SWNT-COOH composite (PMNT-COOH) by employing a simple sonication-driven periodic functionalization strategy. When the PMNT-COOH nanocomposite was used as the anode material for Lithium-ion batteries (LIBs), PMNT-COOH(3) (CuPWNC:SWNT-COOH=3:1) showed superior behavior of energy storage, a high reversible capacity of 885 mA h g^-1 up to a cycle life of 170 cycles. The electrochemical results indicate that the uniform packing of SWNT-COOH provided a favored contact between the electrolyte and the electrode, resulting in enhanced specific capacity during lithium insertion/extraction process. This fabrication of PMNT-COOH nanocomposite opens new avenues for the design and synthesis of new generation electrode materials for LIBs.

In Situ Synthesis of Multilayer Carbon Matrix Decorated with Copper Particles: Enhancing the Performance of Si as Anode for Li-Ion Batteries

A 3D structured composite was designed to improve the conductivity and to ease the volume problems of Si anode during cycling for lithium-ions batteries. An in situ method via a controllable gelation process was explored to fabricate the 3D composite of a multilayer carbon matrix toughened by cross-linked carbon nanotubes (CNTs) and decorated with conductive Cu agents. Structurally, a bifunctional carbon shell was formed on the surface of Si to improve the conductivity but alleviate side reactions. Cu particles as conducting agents decorated in the carbon matrix are also used to further improve the conductivity. The volume issue of Si particles can be effectively released via toughening the carbon matrix through the multilayered structure and cross-linked CNTs. Moreover, the carbon matrix might prevent silicon particles from agglomeration. Consequently, the Si@C@Cu composite is expected to exhibit benign electrochemical performances with a commendable capacity of 1500 mAh g^-1 (900 cycles, 1 A g^-1) and a high rate performance (1035 mAh g^-1, 4 A g^-1). The D_Li⁺ ranging from 10^-11 to 10^-9 cm^-2 s^-1 of the Si@C@Cu anode is obtained via the GITT test, which is higher than most reported data.

Shell-Protective Secondary Silicon Nanostructures as Pressure-Resistant High-Volumetric-Capacity Anodes for Lithium-Ion Batteries

The nanostructure design of a prereserved hollow space to accommodate 300% volume change of silicon anodes has created exciting promises for high-energy batteries. However, challenges with weak mechanical stability during the calendering process of electrode fabrication and poor volumetric energy density remain to be solved. Here we fabricated a pressure-resistant silicon structure by designing a dense silicon shell coating on secondary micrometer particles, each consisting of many silicon nanoparticles. The silicon skin layer significantly improves mechanical stability, while the inner porous structure efficiently accommodates the volume expansion. Such a structure can resist a high pressure of over 100 MPa and is well-maintained after the calendering process, demonstrating a high volumetric capacity of 2041 mAh cm^-3. In addition, the dense silicon shell decreases the surface area and thus increases the initial Coulombic efficiency. With further encapsulation with a graphene cage, which allows the silicon core to expand within the cage while retaining electrical contact, the silicon hollow structure exhibits a high initial Coulombic efficiency and fast rise of later Coulombic efficiencies to >99.5% and superior stability in a full-cell battery.

Controlling electric potential to inhibit solid-electrolyte interphase formation on nanowire anodes for ultrafast lithium-ion batteries

With increasing demand for high-capacity and rapidly rechargeable anodes, problems associated with unstable evolution of a solid-electrolyte interphase on the active anode surface become more detrimental. Here, we report the near fatigue-free, ultrafast, and high-power operations of lithium-ion battery anodes employing silicide nanowires anchored selectively to the inner surface of graphene-based micro-tubular conducting electrodes. This design electrically shields the electrolyte inside the electrode from an external potential load, eliminating the driving force that generates the solid-electrolyte interphase on the nanowire surface. Owing to this electric control, a solid-electrolyte interphase develops firmly on the outer surface of the graphene, while solid-electrolyte interphase-free nanowires enable fast electronic and ionic transport, as well as strain relaxation over 2000 cycles, with 84% capacity retention even at ultrafast cycling (>20C). Moreover, these anodes exhibit unprecedentedly high rate capabilities with capacity retention higher than 88% at 80C (vs. the capacity at 1C).

MXene-Based Electrode with Enhanced Pseudocapacitance and Volumetric Capacity for Power-Type and Ultra-Long Life Lithium Storage

Powerful yet thinner lithium-ion batteries (LIBs) are eagerly desired to meet the practical demands of electric vehicles and portable electronic devices. However, the use of soft carbon materials in current electrode design to improve the electrode conductivity and stability does not afford high volumetric capacity due to their low density and capacity for lithium storage. Herein, we report a strategy leveraging the MXene with superior conductivity and density to soft carbon as matrix and additive material for comprehensively enhancing the power capability, lifespan, and volumetric capacity of conversion-type anode. A kinetics favorable 2D nanohybrid with high conductivity, compact density, accumulated pseudocapacitance, and diffusion-controlled behavior is fabricated by coupling Ti3C2 MXene with high-density molybdenum carbide for fast lithium storage over 300 cycles with high capacities. By replacing the carbonaceous conductive agent with Ti3C2 MXene, the electrodes with better conductivity and dramatically reduced thickens could be further manufactured to achieve 37-40% improvement in capacity retention and ultra-long life of 5500 cycles with extremely slow capacity loss of 0.002% per cycle at high current rates. Ultrahigh volumetric capacity of 2460 mAh cm-3 could be attained by such MXene-based electrodes, highlighting the great promise of MXene in the development of high-performance LIBs.

Caging tin oxide in three-dimensional graphene networks for superior volumetric lithium storage

Tin and its compounds hold promise for the development of high-capacity anode materials that could replace graphitic carbon used in current lithium-ion batteries. However, the introduced porosity in current electrode designs to buffer the volume changes of active materials during cycling does not afford high volumetric performance. Here, we show a strategy leveraging a sulfur sacrificial agent for controlled utility of void space in a tin oxide/graphene composite anode. In a typical synthesis using the capillary drying of graphene hydrogels, sulfur is employed with hard tin oxide nanoparticles inside the contraction hydrogels. The resultant graphene-caged tin oxide delivers an ultrahigh volumetric capacity of 2123 mAh cm^-3 together with good cycling stability. Our results suggest not only a conversion-type composite anode that allows for good electrochemical characteristics, but also a general synthetic means to engineering the packing density of graphene nanosheets for high energy storage capabilities in small volumes.

Nanoscale Heterogeneity of Multilayered Si Anodes with Embedded Nanoparticle Scaffolds for Li-Ion Batteries

A new approach on the synthesis of Si anodes for Li-ion batteries is reported, combining advantages of both nanoparticulated and continuous Si films. A multilayered configuration prototype is proposed, comprising amorphous Si arranged in nanostructured, mechanically heterogeneous films, interspersed with Ta nanoparticle scaffolds. Particular structural features such as increased surface roughness, nanogranularity, and porosity are dictated by the nanoparticle scaffolds, boosting the lithiation process due to fast Li diffusion and low electrode polarization. Consequently, a remarkable charge/discharge speed is reached with the proposed anode, in the order of minutes (1200 mAh g^-1 at 10 C). Moreover, nanomechanical heterogeneity self-limits the capacity at intermediate charge/discharge rates; as a consequence, exceptional cycleability is observed at 0.5 C, with 100% retention over 200 cycles with 700 mAh g^-1. Higher capacity can be obtained when the first cycles are performed at 0.2 C, due to the formation of microislands, which facilitate the swelling of the active Si. This study indicates a method to tune the mechanical, morphological, and electrochemical properties of Si electrodes via engineering nanoparticle scaffolds, paving the way for a novel design of nanostructured Si electrodes for high-performance energy storage devices.

Surface Coating Constraint Induced Anisotropic Swelling of Silicon in Si-Void@SiO x Nanowire Anode for Lithium-Ion Batteries

Here a simple and an environmentally friendly approach is developed for the fabrication of Si-void@SiO_x nanowires of a high-capacity Li-ion anode material. The outer surface of the robust SiO_x backbone and the inside void structure in Si-void@SiO_x nanowires appropriately suppress the volume expansion and lead to anisotropic swelling morphologies of Si nanowires during lithiation/delithiation, which is first demonstrated by the in situ lithiation process. Remarkably, the Si-void@SiO_x nanowire electrode exhibits excellent overall lithium-storage performance, including high specific capacity, high rate property, and excellent cycling stability. A reversible capacity of 1981 mAh g^-1 is obtained in the fourth cycle, and the capacity is maintained at 2197 mAh g^-1 after 200 cycles at a current density of 0.5 C. The outstanding overall properties of the Si-void@SiO_x nanowire composite make it a promising anode material of lithium-ion batteries for the power-intensive energy storage applications.

Si nanorod arrays modified with metal–organic segments as anodes in lithium ion batteries

Metal–organic segments (MOSs) were synthesized to composite with Si nanorod (NR) arrays as electrodes in lithium ion batteries (LIBs).

Tuning the Outward to Inward Swelling in Lithiated Silicon Nanotubes via Surface Oxide Coating

Electrochemically induced mechanical degradation hinders the application of Si anodes in advanced lithium-ion batteries. Hollow structures and surface coatings have been often used to mitigate the degradation of Si-based anodes. However, the structural change and degradation mechanism during lithiation/delithiation of hollow Si structures with coatings remain unclear. Here, we combine in situ TEM experiment and chemomechanical modeling to study the electrochemically induced swelling of amorphous-Si (a-Si) nanotubes with different thicknesses of surface SiOx layers. Surprisingly, we find that no inward expansion occurs at the inner surface during lithiation of a-Si nanotubes with native oxides. In contrast, inward expansion can be induced by increasing the thickness of SiOx on the outer surface, thus reducing the overall outward swelling of the lithiated nanotube. Moreover, both the sandwich lithiation mechanism and the two-stage lithiation process in a-Si nanotubes remain unchanged with the increasing thickness of surface coatings. Our chemomechanical modeling reveals the mechanical confinement effects in lithiated a-Si nanotubes with and without SiOx coatings. This work not only provides insights into the degradation of nanotube anodes with surface coatings but also sheds light onto the optimal design of hollow anodes for high-performance lithium-ion batteries.

High Anodic Performance of Co 1,3,5-Benzenetricarboxylate Coordination Polymers for Li-Ion Battery

We report the designed synthesis of Co 1,3,5-benzenetricarboxylate coordination polymers (CPs) via a straightforward hydrothermal method, in which three kinds of reaction solvents are selected to form CPs with various morphologies and dimensions. When tested as anode materials in Li-ion battery, the cycling stabilities of the three CoBTC CPs at a current density of 100 mA g(-1) have not evident difference; however, the reversible capacities are widely divergent when the current density is increased to 2 A g(-1). The optimized product CoBTC-EtOH maintains a reversible capacity of 473 mAh g(-1) at a rate of 2 A g(-1) after 500 galvanostatic charging/discharging cycles while retaining a nearly 100% Coulombic efficiency. The hollow microspherical morphology, accessible specific area, and the absence of coordination solvent of CoBTC-EtOH might be responsible for such difference. Furthermore, the ex situ soft X-ray absorption spectroscopy studies of CoBTC-EtOH under different states-of-charge suggest that the Co ions remain in the Co(2+) state during the charging/discharging process. Therefore, Li ions are inserted to the organic moiety (including the carboxylate groups and the benzene ring) of CoBTC without the direct engagement of Co ions during electrochemical cycling.

Well-constructed silicon-based materials as high-performance lithium-ion battery anodes

Silicon has been considered as one of the most promising anode material alternates for next-generation lithium-ion batteries, because of its high theoretical capacity, environmental friendliness, high safety, low cost, etc. Nevertheless, silicon-based anode materials (especially bulk silicon) suffer from severe capacity fading resulting from their low intrinsic electrical conductivity and great volume variation during lithiation/delithiation processes. To address this challenge, a few special constructions from nanostructures to anchored, flexible, sandwich, core-shell, porous and even integrated structures, have been well designed and fabricated to effectively improve the cycling performance of silicon-based anodes. In view of the fast development of silicon-based anode materials, we summarize their recent progress in structural design principles, preparation methods, morphological characteristics and electrochemical performance by highlighting the material structure. We also point out the associated problems and challenges faced by these anodes and introduce some feasible strategies to further boost their electrochemical performance. Furthermore, we give a few suggestions relating to the developing trends to better mature their practical applications in next-generation lithium-ion batteries.

Freestanding rGO-SWNT-STN Composite Film as an Anode for Li Ion Batteries with High Energy and Power Densities

Freestanding Si-Ti-Ni alloy particles/reduced graphene oxide/single wall carbon nanotube composites have been prepared as an anode for lithium ion batteries via a simple filtration method. This composite electrode showed a 9% increase in reversible capacity, a two-fold higher cycle retention at 50 cycles and a two-fold higher rate capability at 2 C compared to pristine Si-Ti-Ni (STN) alloy electrodes. These improvements were attributed to the suppression of the pulverization of the STN active material by the excellent mechanical properties of the reduced graphene oxide-single wall carbon nanotube networks and the enhanced kinetics associated with both electron and Li ion transport.

Graphene as an Interfacial Layer for Improving Cycling Performance of Si Nanowires in Lithium-Ion Batteries

Managing interfacial instability is crucial for enhancing cyclability in lithium-ion batteries (LIBs), yet little attention has been devoted to this issue until recently. Here, we introduce graphene as an interfacial layer between the current collector and the anode composed of Si nanowires (SiNWs) to improve the cycling capability of LIBs. The atomically thin graphene lessened the stress accumulated by volumetric mismatch and inhibited interfacial reactions that would accelerate the fatigue of Si anodes. By simply incorporating graphene at the interface, we demonstrated significantly enhanced cycling stability for SiNW-based LIB anodes, with retentions of more than 2400 mAh/g specific charge capacity over 200 cycles, 2.7 times that of SiNWs on a bare current collector.

Amorphous silicon honeycombs as a binder/carbon-free, thin-film Li-ion battery anode

Amorphous silicon thin films with honeycombed structures have been prepared using a self-assembled monolayer of polystyrene spheres as the template. The as-prepared thin films may serve as a good anode candidate for thin film Li-ion batteries. This approach can be extended to a wide range of coating materials and substrates with controlled periodic structures.

Core-shell Si/C nanospheres embedded in bubble sheet-like carbon film with enhanced performance as lithium ion battery anodes

Due to its high theoretical capacity and low lithium insertion voltage plateau, silicon has been considered one of the most promising anodes for high energy and high power density lithium ion batteries (LIBs). However, its rapid capacity degradation, mainly caused by huge volume changes during lithium insertion/extraction processes, remains a significant challenge to its practical application. Engineering Si anodes with abundant free spaces and stabilizing them by incorporating carbon materials has been found to be effective to address the above problems. Using sodium chloride (NaCl) as a template, bubble sheet-like carbon film supported core-shell Si/C composites are prepared for the first time by a facile magnesium thermal reduction/glucose carbonization process. The capacity retention achieves up to 93.6% (about 1018 mAh g(-1)) after 200 cycles at 1 A g(-1). The good performance is attributed to synergistic effects of the conductive carbon film and the hollow structure of the core-shell nanospheres, which provide an ideal conductive matrix and buffer spaces for respectively electron transfer and Si expansion during lithiation process. This unique structure decreases the charge transfer resistance and suppresses the cracking/pulverization of Si, leading to the enhanced cycling performance of bubble sheet-like composite.

Engineering three-dimensionally electrodeposited Si-on-Ni inverse opal structure for high volumetric capacity Li-ion microbattery anode

Aiming at improving the volumetric capacity of nanostructured Li-ion battery anode, an electrodeposited Si-on-Ni inverse opal structure has been proposed in the present work. This type of electrode provides three-dimensional bi-continuous pathways for ion/electron transport and high surface area-to-volume ratios, and thus exhibits lower interfacial resistance, but higher effective Li ions diffusion coefficients, when compared to the Si-on-Ni nanocable array electrode of the same active material mass. As a result, improved volumetric capacities and rate capabilities have been demonstrated in the Si-on-Ni inverse opal anode. We also show that optimization of the volumetric capacities and the rate performance of the inverse opal electrode can be realized by manipulating the pore size of the Ni scaffold and the thickness of the Si deposit.

Germanium nanoparticles encapsulated in flexible carbon nanofibers as self-supported electrodes for high performance lithium-ion batteries

Germanium is a promising high-capacity anode material for lithium ion batteries, but still suffers from poor cyclability due to its huge volume variation during the Li-Ge alloy/dealloy process. Here we rationally designed a flexible and self-supported electrode consisting of Ge nanoparticles encapsulated in carbon nanofibers (Ge-CNFs) by using a facile electrospinning technique as potential anodes for Li-ion batteries. The Ge-CNFs exhibit excellent electrochemical performance with a reversible specific capacity of ∼1420 mA h g(-1) after 100 cycles at 0.15 C with only 0.1% decay per cycle (the theoretical specific capacity of Ge is 1624 mA h g(-1)). When cycled at a high current of 1 C, they still deliver a reversible specific capacity of 829 mA h g(-1) after 250 cycles. The strategy and design are simple, effective, and versatile. This type of flexible electrodes is a promising solution for the development of flexible lithium-ion batteries with high power and energy densities.

The effects of different core-shell structures on the electrochemical performances of Si-Ge nanorod arrays as anodes for micro-lithium ion batteries

Connected and airbag isolated Si-Ge nanorod (NR) arrays in different configurations have been fabricated on wafer scale Si substrates as anodes in micro-lithium ion batteries (LIBs), and the impacts of configurations on electrochemical properties of the electrodes were investigated experimentally and theoretically. It is demonstrated that the Si inner cores can be effectively protected by the connected Ge shells and contribute to the enhanced capacity by ∼68%, derived from an activation process along with the amorphization of the crystalline lattice. The first-principles calculations further verify the smaller forces on the Si layers at the atomic level during the restricted volume expansion with the covering of Ge layers. This work provides general guidelines for designing other composites and core-shell configurations in electrodes of micro-LIBs to accomplish higher capacities and longer cycle lives.

One-Dimensional Silicon Nanostructures for Li Ion Batteries

One dimensional (1D) silicon nanostructures have attracted significant interest as an anode material for lithium ion batteries (LIBs) as its 1D geometry accommodates the large volume change of the Si during cycling and enables facile electron transport during all stages of operation. Furthermore, the high aspect ratio of 1D Si nanostructures enables us to investigate atomic-scale mechanisms of the lithiation process and corresponding volume change behavior. Various 1D nanostructures with different morphologies and compositions have been explored to achieve a robust cycle performance, reversible morphological changes, and high rate capabilities. In this Perspective, we summarize the recent significant advances of 1D Si nanostructures and discuss electrode design strategies based on the recent geometry and composition engineering.

Enhanced cycling stability of silicon anode by in situ polymerization of poly(aniline-co-pyrrole)

Poly(aniline-co-pyrrole)-encapsulated Si nanoparticles composite anode material were prepared by an in situ chemical oxidation polymerization method.

High volumetric capacity silicon-based lithium battery anodes by nanoscale system engineering

The nanostructuring of silicon (Si) has recently received great attention, as it holds potential to deal with the dramatic volume change of Si and thus improve lithium storage performance. Unfortunately, such transformative materials design principle has generally been plagued by the relatively low tap density of Si and hence mediocre volumetric capacity (and also volumetric energy density) of the battery. Here, we propose and demonstrate an electrode consisting of a textured silicon@graphitic carbon nanowire array. Such a unique electrode structure is designed based on a nanoscale system engineering strategy. The resultant electrode prototype exhibits unprecedented lithium storage performance, especially in terms of volumetric capacity, without the expense of compromising other components of the battery. The fabrication method is simple and scalable, providing new avenues for the rational engineering of Si-based electrodes simultaneously at the individual materials unit scale and the materials ensemble scale.