Gongkai Wang

Carbon materials possess attractive mechanical and thermal properties, yet creating bulk sp²-bonded carbon that unites high hardness, elastic recoverability, and thermal stability has remained elusive. Mechanical anisotropy, low damage tolerance, and structural instability under stress or at high temperatures hinder the development of dense sp²-carbon architectures for demanding environments. Here we report a dual-phase sp² carbon produced from C₆₀ at high pressure through progressive structural reconstruction, yielding a hierarchical structure in which stacked graphene nanoclusters are integrated within a disordered sp²-rich amorphous matrix. This architecture accommodates stress by structurally mediated interlayer sliding and elastic compaction, while retaining structural coherence. The resulting material achieves ~ 20 GPa hardness, > 88% elastic recovery, and oxidation resistance near 960 °C in air, representing an unusual combination of mechanical recoverability and thermal stability among representative carbon materials. Simulations show that the combination of stiffness and resilience arises from interfacial reinforcement between the ordered and disordered domains. This work identifies a structural pathway for engineering sp²-carbon systems that overcome long-standing limits in mechanical and thermal performance.

Anode‐free sodium metal batteries (AFSMBs) are promising for high‐energy‐density storage but are limited by poor Na plating/stripping reversibility on conventional current collectors, where insufficient sodiophilicity and unstable interfacial chemistry induce uneven sodium deposition and rapid sodium inventory loss. Here, an in situ interfacial reconstruction strategy is developed on an Al current collector by introducing SnF ₂ into a PVDF‐HFP layer. A hot‐pressing‐induced redox reaction forms a prefabricated interfacial layer containing metallic Sn and AlF ₃ , which further evolves during initial sodiation into a NaF‐rich organic/inorganic composite interphase. The uniformly distributed metallic Sn sites markedly reduce the Na nucleation barrier and promote high‐density nucleation, while the fluorine‐rich interphase lowers the Na ⁺ transport barrier and stabilizes the anode interface. Through the coupled regulation of nucleation behavior, ion transport, and interfacial stability, the reconstructed current collector enables dense and highly reversible Na deposition. As a result, asymmetric cells achieve 450 cycles at 5 mAh cm ⁻² with an average CE of 99.91%, symmetric cells sustain stable cycling for over 1300 h at 90% depth of discharge, and AFSMBs deliver 84% capacity retention and 330 Wh kg ⁻¹ under a cathode loading of 35.17 mg cm ⁻² . This work offers an effective interfacial engineering strategy for practical AFSMBs.

Alloy-type metal foils are attractive anodes for high-energy lithium-ion batteries because they eliminate inactive electrode components while providing high volumetric capacity. However, their practical implementation is hindered by a fundamental transport–mechanics conflict. Uniform alloying reactions require open ion pathways, whereas suppressing large lithiation-induced volume strain demands strong mechanical confinement. Here, we demonstrate that this conflict can be mitigated by regulating the spatial continuity of the Al phase in multilayer Sn foil anodes. In contrast to pure Sn multilayers that undergo severe pulverization and continuous Al/Sn laminates that impose a Li+ transport barrier, a mesh-derived discontinuous Al skeleton embedded in a continuous Sn network simultaneously preserves Li+ accessibility and redistributes alloying-induced stress. The optimized AlmSn-ML anode sustains 430 cycles at 2 mAh cm−2 and 1 mA cm−2, while full cells paired with high-loading LiFePO4 (LFP) cathodes retain 91.51% capacity after 160 cycles. Moreover, AlmSn-ML/Li0.8Co0.1Mn0.1O2 (NCM811) full cells deliver a high volumetric energy density. These findings highlight topology-regulated mechanical reinforcement as an effective strategy for developing low-strain, high-capacity foil anodes.

Achieving high‐energy‐density lithium‐ion batteries (LIBs) requires silicon (Si) anodes that can operate reliably under the high compaction densities demanded by practical cells. However, severe volume fluctuations and unstable interfacial chemistry continue to induce mechanical failure and rapid performance decay. Here, we introduce a hierarchically engineered composite anode (NSi ₅₀ /PSi@C) that integrates a porous silicon scaffold, infiltrated nano‐silicon (NSi), and a conformal carbon coating. This architecture creates a continuous electron‐conducting network, homogenizes stress distribution through nanoscale Si buffering, and preserves ion diffusion channels by preventing pore collapse. Coupled with a mechanically compliant carbon shell that stabilizes the solid electrolyte interphase (SEI) and maintains interfacial integrity, the electrode exhibits significantly improved charge‐transfer kinetics and structural robustness. Benefiting from this multi‐level design, NSi ₅₀ /PSi@C achieves a high compaction density of 1.38 g cm ⁻³ while delivering 1316.6 mAh g ⁻¹ after 300 cycles with only 38% thickness expansion. The anode maintains >600 mAh g ⁻¹ at 5 A g ⁻¹ and demonstrates stable operation at elevated areal loadings. These results validate an effective design principle that simultaneously addresses mechanical, interfacial, and kinetic limitations, offering a scalable pathway toward practical, high‐density silicon anodes for next‐generation LIBs.

Alloy‐type anodes possess ultrahigh theoretical capacities but suffer from severe volume expansion and mechanical degradation during cycling, impeding their practical application in lithium‐ion batteries (LIBs). Here, this work proposes an equilibrium lithiation dynamics strategy to design an indium (In)‐tin (Sn) alloy‐type foil anode that effectively mitigates bulk strain through intrinsic strain partitioning. The incorporation of In regulates the lithiation pathway of Sn by forming a LiInSn intermediate phase with high Li ⁺ diffusivity, which promotes a balanced and homogeneous phase transition. This kinetically optimized lithiation process significantly reduces localized stress accumulation and enables uniform strain distribution throughout the electrode. Benefiting from this synergistic mechanism, the InSn foil exhibits only 27.2% volumetric expansion under practically relevant conditions (2 mAh cm ⁻² , 100 cycles), setting a benchmark in strain management for alloy anodes. Its interlocking structure forms a stable solid‐solid interface that dissipates stress efficiently, ensuring mechanical robustness and fast Li ⁺ transport. The anode delivers high Coulombic efficiency (>99.5%) and excellent cycling stability. Full cells (InSn‐E||LFP, InSn‐E||NCM811) achieve 96.9% capacity retention after 500 cycles and over 1300 Wh L ⁻¹ . This work establishes a paradigm of equilibrium‐driven strain partitioning for alloy‐type anodes, offering both mechanistic insight and a practical pathway toward high‐energy‐density LIBs.

Micro-sized silicon (μSi) is a promising anode for next-generation high-energy-density lithium-ion batteries (LIBs) due to its high capacity and excellent tap density. However, its severe volume fluctuations induce mechanical degradation and rapid capacity fading. Here, we develop a strain-adaptive design to construct hierarchical Si/graphene composite microspheres (DSMG@C) via scalable spray-drying and chemical vapor deposition (CVD). The architecture integrates an internal graphene scaffold, dual-scale (micro/nano) silicon, and a conformal ∼10 nm graphitic carbon shell, enabling an internal compliant framework with distributed microvoids coupled with an external conformal carbon confinement layer. The graphene-based framework and distributed microvoids accommodate local deformation, while nano-Si serves as an adaptive interstitial filler to densify contacts and disperse stress. The nano-Si disperses stress and fills voids to enhance densification, while the carbon shell reinforces mechanical stability and interfacial robustness. As a result, the DSMG@C anode delivers a high reversible capacity of 1062.8 mAh g⁻¹ after 500 cycles at 1 A g⁻¹, an initial coulombic efficiency of 90.8%, and a superior volumetric capacity owing to its 1.22 g cm⁻³ compacted density. Kinetic and mechanical analyses confirm its fast ion/electron transport and durable structural integrity. Full cells paired with LiFePO₄ exhibit a discharge capacity of 123.4 mAh g⁻¹ at 1 C after 200 cycles with an initial coulombic efficiency (ICE) of 92.7%, demonstrating strong practical potential. This work offers an effective strategy for designing high-performance Si-based anodes through multiscale structural engineering.

The rapid global accumulation of retired wind turbine blades (RWTBs) has emerged as a critical environmental challenge requiring urgent resolution. Conventional recycling methods, primarily limited to landfilling, construction fillers, and co‐processing in cement production, fail to achieve true resource circularity. To address this pressing issue, this study pioneers an innovative value‐added utilization strategy that successfully converts glass fibers from RWTBs into high‐performance silicon–carbon (Si─C) composite anodes for next‐generation lithium‐ion batteries (LIBs). By integrating an alloying reaction‐nitridation treatment with precisely optimized chemical vapor deposition (CVD), we constructed a hierarchically porous recycled micron‐sized silicon (rP‐Si) scaffold structure with uniform carbon coating. The resulting rP‐Si@C composite exhibits exceptional electrochemical performance, maintaining a specific capacity of 1256 mAh g ⁻¹ after 300 cycles at 1 A g ⁻¹ while demonstrating exceptional structural integrity against mechanical deformation. Systematic characterization via advanced analytical techniques confirms that the unique multi‐level architecture not only effectively accommodates significant volume changes during cycling but also significantly enhances lithium‐ion (Li ⁺ ) diffusion kinetics. This work establishes a feasible technological pathway for the sustainable transformation of RWTBs into advanced energy storage components, thereby constructing a complete closed‐loop ecosystem for renewable energy infrastructure.