High‐Performance Sb/Sb2O3 Anode Materials Using a Polypyrrole Nanowire Network for Na‐Ion Batteries

Three‐dimensional porous Sb/Sb₂O₃ anode materials are successfully fabricated using a simple electrodeposition method with a polypyrrole nanowire network. The Sb/Sb₂O₃–PPy electrode exhibits excellent cycle performance and outstanding rate capabilities; the charge capacity is sustained at 512.01 mAh g^?1 over 100 cycles, and 56.7% of the charge capacity at a current density of 66 mA g^?1 is retained at 3300 mA g^?1. The improved electrochemical performance of the Sb/Sb₂O₃–PPy electrode is attributed not only to the use of a highly porous polypyrrole nanowire network as a substrate but also to the buffer effects of the Sb₂O₃ matrix on the volume expansion of Sb. Ex situ scanning electron microscopy observation confirms that the Sb/Sb₂O₃–PPy electrode sustains a strong bond between the nanodeposits and polypyrrole nanowires even after 100 cycles, which maintains good electrical contact of Sb/Sb₂O₃ with the current collector without loss of the active materials.     

脉冲激光液相烧蚀贵金属Au/Ag产物的表征及反应机理研究

采用多波长(1064nm、532nm、248nm)脉冲激光在去离子水中对责金属Au、Ag片表面进行激光烧蚀(PLA).利用TEM、AFM、SEM对烧蚀金属片表层及产物(微/纳米尺度的金属颗粒)进行观察分析,认为在液相水环境中,整个烧蚀过程主要可分为激光诱导相沸腾爆炸和等离子体羽辉混合体膨胀2个过程.在这2个过程中分别产生得到具有微米尺度的球状金属颗粒和纳米尺度的金属颗粒.同时,具有纳米尺度金属Au/Ag颗粒经过强激光光子"二次"修饰改性过程,形成具有形状统一、分散性和稳定性较好的金属纳米胶体体系,这些胶体中金属纳米颗粒作为探针,在表面增强拉曼散射(SERS)光谱学方面有很好的应用价值.     

In Situ Mesopore Formation in SiOx Nanoparticles by Chemically Reinforced Heterointerface and Use of Chemical Prelithiation for Highly Reversible Lithium-Ion Battery Anode (Small 16/2023)

SiO_x is a promising next-generation anode material for lithium-ion batteries. However, its commercial adoption faces challenges such as low electrical conductivity, large volume expansion during cycling, and low initial Coulombic efficiency. Herein, to overcome these limitations, an eco-friendly in situ methodology for synthesizing carbon-containing mesoporous SiO_x nanoparticles wrapped in another carbon layers is developed. The chemical reactions of vinyl-terminated silanes are designed to be confined inside the cationic surfactant-derived emulsion droplets. The polyvinylpyrrolidone-based chemical functionalization of organically modified SiO₂ nanoparticles leads to excellent dispersion stability and allows for intact hybridization with graphene oxide sheets. The formation of a chemically reinforced heterointerface enables the spontaneous generation of mesopores inside the thermally reduced SiO_x nanoparticles. The resulting mesoporous SiO_x-based nanocomposite anodes exhibit superior cycling stability (≈100% after 500 cycles at 0.5 A g⁻¹) and rate capability (554 mAh g⁻¹ at 2 A g⁻¹), elucidating characteristic synergetic effects in mesoporous SiO_x-based nanocomposite anodes. The practical commercialization potential with a significant enhancement in initial Coulombic efficiency through a chemical prelithiation reaction is also presented. The full cell employing the prelithiated anode demonstrated more than 2 times higher Coulombic efficiency and discharge capacity compared to the full cell with a pristine anode.     

SnO2 Quantum Dots: Rational Design to Achieve Highly Reversible Conversion Reaction and Stable Capacities for Lithium and Sodium Storage

SnO₂ has been considered as a promising anode material for lithium‐ion batteries (LIBs) and sodium ion batteries (SIBs), but challenging as well for the low‐reversible conversion reaction and coulombic efficiency. To address these issues, herein, SnO₂ quantum dots (≈5 nm) embedded in porous N‐doped carbon matrix (SnO₂/NC) are developed via a hydrothermal step combined with a self‐polymerization process at room temperature. The ultrasmall size in quantum dots can greatly shorten the ion diffusion distance and lower the internal strain, improving the conversion reaction efficiency and coulombic efficiency. The rich mesopores/micropores and highly conductive N‐doped carbon matrix can further enhance the overall conductivity and buffer effect of the composite. As a result, the optimized SnO₂/NC‐2 composite for LIBs exhibits a high coulombic efficiency of 72.9%, a high discharge capacity of 1255.2 mAh g^?1 at 0.1 A g^?1 after 100 cycles and a long life‐span with a capacity of 753 mAh g^?1 after 1500 cycles at 1 A g^?1. The SnO₂/NC‐2 composite also displays excellent performance for SIBs, delivering a superior discharge capacity of 212.6 mAh g^?1 at 1 A g^?1 after 3000 cycles. These excellent results can be of visible significance for the size effect of the uniform quantum dots.     

Novel Structural Design and Adsorption/Insertion Coordinating Quasi-Metallic Na Storage Mechanism toward High-performance Hard Carbon Anode Derived from Carboxymethyl Cellulose

Hard Carbon have become the most promising anode candidates for sodium-ion batteries, but the poor rate performance and cycle life remain key issues. In this work, N-doped hard carbon with abundant defects and expanded interlayer spacing is constructed by using carboxymethyl cellulose sodium as precursor with the assistance of graphitic carbon nitride. The formation of N-doped nanosheet structure is realized by the C N• or C C• radicals generated through the conversion of nitrile intermediates in the pyrolysis process. This greatly enhances the rate capability (192.8 mAh g⁻¹ at 5.0 A g⁻¹) and ultra-long cycle stability (233.3 mAh g⁻¹ after 2000 cycles at 0.5 A g⁻¹). In situ Raman spectroscopy, ex situ X-ray diffraction and X-ray photoelectron spectroscopy analysis in combination with comprehensive electrochemical characterizations, reveal that the interlayer insertion coordinated quasi-metallic sodium storage in the low potential plateau region and adsorption storage in the high potential sloping region. The first-principles density functional theory calculations further demonstrate strong coordination effect on nitrogen defect sites to capture sodium, especially with pyrrolic N, uncovering the formation mechanism of quasi-metallic bond in the sodium storage. This work provides new insights into the sodium storage mechanism of high-performance carbonaceous materials, and offers new opportunities for better design of hard carbon anode.     

RuO2 Particles Anchored on Brush‐Like 3D Carbon Cloth Guide Homogenous Li/Na Nucleation Framework for Stable Li/Na Anode

Lithium (sodium)‐metal batteries are the most promising batteries for next‐generation electrical energy storage due to their high volumetric energy density and gravimetric energy density. However, their applications have been prevented by uncontrollable dendrite growth and large volume expansion during the stripping/plating process. To address this issue, the key strategy is to realize uniform lithium (sodium) deposition during the stripping/plating process. Herein, a thin lithiophilic layer consisting of RuO₂ particles anchored on brush‐like 3D carbon cloth (RuO₂@CC) is prepared by a simple solution‐based method. After infusion of Li, the RuO₂@CC transfers to Li‐Ru@CC. Ru nanoparticles not only play a role in leading Li⁺ (Na⁺) to plate on the 3D carbon framework, but also lower local current density because of the good electrical conductivity. Furthermore, density functional theory calculations demonstrate that Ru metal, the reaction product of alkali metal and Ru, can lead Li⁺ to plate evenly around carbon fiber owing to the strong binding energy with Li⁺. The Li‐Ru@CC anode shows ultralong cycle life (1500 h at 5 mA cm^?2). The full cell of Li‐Ru@CC|LiFePO₄ exhibits lower polarization (90% capacity retention after 650 cycles). In addition, sodium metal batteries based on Na‐Ru@CC anodes can achieve similar improvement.     

Reduced Aggregation and Cytotoxicity of Amyloid Peptides by Graphene Oxide/Gold Nanocomposites Prepared by Pulsed Laser Ablation in Water

A novel and convenient method to synthesize the nanocomposites combining graphene oxides (GO) with gold nanoparticles (AuNPs) is reported and their applications to modulate amyloid peptide aggregation are demonstrated. The nanocomposites produced by pulsed laser ablation (PLA) in water show good biocompatibility and solubility. The reduced aggregation of amyloid peptides by the nanocomposites is confirmed by Thioflavin T fluorescence and atomic force microscopy. The cell viability experiments reveals that the presence of the nanocomposites can significantly reduce the cytotoxicity of the amyloid peptides. Furthermore, the depolymerization of peptide fibrils and inhibition of their cellular cytotoxicity by GO/AuNPs is also observed. These observations suggest that the nanocomposites combining GO and AuNPs have a great potential for designing new therapeutic agents and are promising for future treatment of amyloid‐related diseases.     

Confined Assembly of Hydrated Vanadium Oxide into Hollow Mesoporous Carbon Nanospheres for Fast and Stable K+ Storage Capability

The rational structural design of the electrode materials is significant to enhance the electrochemical performance for potassium ion storage, benefiting from the shortened ion diffusion distance, increased conductivity, and pseudo-capacitance promotion. Herein, hydrated vanadium oxide (HVO) nanosheets with enriched oxygen defects are well confined into hollow mesoporous carbon spheres (HMCS), producing O_d-VOH@C nanospheres through one-step hydrothermal reaction. Attributed to the restricted growth in the HMCS, the HVO nanosheets are loosely packed, generating abundant interfacial boundaries and large specific areas. As a result, O_d-VOH@C nanospheres show increased reaction kinetics and well buffer the volume effects for the K⁺ storage. O_d-VOH@C delivers stable capacities of 138 mAh g⁻¹ at 2.0 A g⁻¹ over 10 000 cycles in half-cells attributed to the high pseudo-capacitance contribution. The K⁺ storage mechanism of insertion and conversion reaction is confirmed by ex situ X-ray diffraction, Raman, and X-ray photoelectron spectroscopy analyses. Moreover, the symmetric potassium-ion capacitors of O_d-VOH@C//O_d-VOH@C deliver a high energy density of 139.6 Wh kg⁻¹ at the power density of 948.3 W kg⁻¹.     

Therapeutic Window for Bioactive Nanocomposites Fabricated by Laser Ablation in Polymer‐Doped Organic Liquids

Polymeric nanomaterials are gaining increased interest in medical applications due to the sustained release of bioactive agents. Within this study nanomaterials are fabricated using laser ablation of silver and copper in polymer‐doped organic liquids thus allowing to produce customized drug release systems. A strategy is shown to determine the therapeutic window for cells relevant for cochlear implant electrodes, defined by the viability of L929 fibroblasts, PC12 neuronal cells, and spiral ganglion cells on different concentrations of silver and copper ions. The distribution of nanoparticles within the silicone polymer matrix is determined using transmission electron microscopy. Hexane doped with 1% silicone resin is found to be an appropriate liquid matrix to fabricate a nanocomposite with a constant ion release rate. Silver ions of 10 µmol L^?1 or copper ions of 100 µmol L^?1 cause a suppression of tissue growth without inhibiting neuronal cell growth. The copper nanoparticle content of 0.1 wt% of the silicone composite releases ion concentrations which fit the therapeutic window.     

钠离子电池中空结构CoSe2/C负极材料的制备及储钠性能研究

过渡金属硒化物具有较高的理论比容量和良好的导电能力, 是钠离子电池潜在的负极材料, 但其在电化学过程中会发生较大体积变化, 循环寿命不佳, 发展受到了限制。为缓解上述问题, 本研究以金属有机框架材料ZIF-67为前驱体, 用单宁酸(Tannic acid, TA)将ZIF-67刻蚀为空心结构, 再通过碳化、硒化制备出以碳为骨架的纳米中空CoSe₂材料(H-CoSe₂/C), 相较于未经刻蚀处理的CoSe₂材料(CoSe₂/C), H-CoSe₂/C表现出更好的储钠性能, 特别是循环稳定性得到显著提高。50 mA·g^-1电流密度下, 经过350次循环, 可逆比容量保持在383.4 mAh·g^-1, 容量保持率为83.6%; 在500 mA·g^-1电流密度下, 经过350次循环后容量保持率仍能达到72.2%。本研究表明, 中空结构能够提供足够的空间以缓解材料在电化学过程中的体积变化, 进而提高电极材料的循环性能。     

脉冲激光沉积金刚石基c轴取向LiNbO3压电薄膜

采用等化学计量比的LiNbO3多晶陶瓷为靶材,利用脉冲激光沉积技术在以非晶SiO2为缓冲层的金刚石/Si衬底上制备c轴取向LiNbO3薄膜。研究了靶材与衬底之间的距离对LiNbO3薄膜的结晶质量和c轴取向性的影响,发现在靶材与衬底之间的距离为4.0cm时获得了具有优异结晶质量的完全c轴取向LiNbO3压电薄膜。采用扫描电子显微镜和原子力显微镜对最佳条件下制备的薄膜进行了分析,结果表明制得的薄膜呈与衬底垂直的柱状结构,且薄膜表面光滑,晶粒均匀致密,表面平均粗糙度约为9.5 nm。     

Nanostructured MoS2 with Interlayer Controllably Regulated by Ionic Liquids/Cellulose for High-Capacity and Durable Sodium Storage Properties

Low intrinsic conductivity and structural instability of MoS₂ as an anode of sodium-ion batteries limit the liberation of its theoretical capacity. Herein, density functional theory simulations for the first time optimize MoS₂ interlayer distance between 0.80 and 1.01 nm for sodium storage. 1-Butyl-3-methyl-imidazolium acetate ([BMIm]Ac) induces cellulose oligomers to intercalate MoS₂ interlayers for achieving controllable distance by changing the mass ratio of cellulose to [BMIm]Ac. Based on these findings, porous carbon loading the interlayer-expanded MoS₂ allowing Na⁺ to insert with fast kinetics is synthesized. A carbon layer derived from [BMIm]Ac and cellulose coating the composite prevents the MoS₂ from contacting electrolytes, leading to less sulfur loss for a more reversible specific capacity. Meanwhile, MoS₂ and carbon have a strong interfacial connection through Mo N binding, contributing to enhanced structural stability. As expected, while cycling 250 times at 0.1 A g^-1, the MoS₂-porous carbon composite displays an optimal reversible capacity at 517.79 mAh g^-1 as a sodium-ion batteries anode. The cyclic test of 1.0 A g^-1 also shows considerable stability (310.74 mAh g^-1 after 1000 cycles with 86.26% retentive capacity). This study will open up new possibilities of modifying MoS₂ that serves as an applicable material as sodium-ion battery anode.     

Ti‐Based Oxide Anode Materials for Advanced Electrochemical Energy Storage: Lithium/Sodium Ion Batteries and Hybrid Pseudocapacitors

Titanium‐based oxides including TiO₂ and M‐Ti‐O compounds (M = Li, Nb, Na, etc.) family, exhibit advantageous structural dynamics (2D ion diffusion path, open and stable structure for ion accommodations) for practical applications in energy storage systems, such as lithium‐ion batteries, sodium‐ion batteries, and hybrid pseudocapacitors. Further, Ti‐based oxides show high operating voltage relative to the deposition of alkali metal, ensuring full safety by avoiding the formation of lithium and sodium dendrites. On the other hand, high working potential prevents the decomposition of electrolyte, delivering excellent rate capability through the unique pseudocapacitive kinetics. Nevertheless, the intrinsic poor electrical conductivity and reaction dynamics limit further applications in energy storage devices. Recently, various work and in‐depth understanding on the morphologies control, surface engineering, bulk‐phase doping of Ti‐based oxides, have been promoted to overcome these issues. Inspired by that, in this review, the authors summarize the fundamental issues, challenges and advances of Ti‐based oxides in the applications of advanced electrochemical energy storage. Particularly, the authors focus on the progresses on the working mechanism and device applications from lithium‐ion batteries to sodium‐ion batteries, and then the hybrid pseudocapacitors. In addition, future perspectives for fundamental research and practical applications are discussed.     

Ultrafast Charge-Discharge Capable and Long-Life Na3.9Mn0.95Zr0.05V(PO4)3/C Cathode Material for Advanced Sodium-Ion Batteries

Na₄MnV(PO₄)₃/C (NMVP) has been considered an attractive cathode for sodium-ion batteries with higher working voltage and lower cost than Na₃V₂(PO₄)₃/C. However, the poor intrinsic electronic conductivity and Jahn–Teller distortion caused by Mn³⁺ inhibit its practical application. In this work, the remarkable effects of Zr-substitution on prompting electronic and Na-ion conductivity and also structural stabilization are reported. The optimized Na_3.9Mn_0.95Zr_0.05V(PO₄)₃/C sample shows ultrafast charge-discharge capability with discharge capacities of 108.8, 103.1, 99.1, and 88.0 mAh g⁻¹ at 0.2, 1, 20, and 50 C, respectively, which is the best result for cation substituted NMVP samples reported so far. This sample also shows excellent cycling stability with a capacity retention of 81.2% at 1 C after 500 cycles. XRD analyses confirm the introduction of Zr into the lattice structure which expands the lattice volume and facilitates the Na⁺ diffusion. First-principle calculation indicates that Zr modification reduces the band gap energy and leads to increased electronic conductivity. In situ XRD analyses confirm the same structure evolution mechanism of the Zr-modified sample as pristine NMVP, however the strong Zr O bond obviously stabilizes the structure framework that ensures long-term cycling stability.     

S‐Doped Carbon Fibers Uniformly Embedded with Ultrasmall TiO2 for Na+/Li+ Storage with High Capacity and Long‐Time Stability

Building a rechargeable battery with high capacity, high energy density, and long lifetime contributes to the development of novel energy storage devices in the future. Although carbon materials are very attractive anode materials for lithium‐ion batteries (LIBs), they present several deficiencies when used in sodium‐ion batteries (SIBs). The choice of an appropriate structural design and heteroatom doping are critical steps to improve the capacity and stability. Here, carbon‐based nanofibers are produced by sulfur doping and via the introduction of ultrasmall TiO₂ nanoparticles into the carbon fibers (CNF‐S@TiO₂). It is discovered that the introduction of TiO₂ into carbon nanofibers can significantly improve the specific surface area and microporous volume for carbon materials. The TiO₂ content is controlled to obtain CNF‐S@TiO₂‐5 to use as the anode material for SIBs/LIBs with enhanced electrochemical performance in Na⁺/Li⁺ storage. During the charge/discharge process, the S‐doping and the incorporation of TiO₂ nanoparticles into carbon fibers promote the insertion/extraction of the ions and enhance the capacity and cycle life. The capacity of CNF‐S@TiO₂‐5 can be maintained at ≈300 mAh g^?1 over 600 cycles at 2 A g^?1 in SIBs. Moreover, the capacity retention of such devices is 94%, showing high capacity and good stability.