Solid State Ionics最新文献

Zn-doped V₂O₅ film electrodes were prepared by in-situ growth on indium‑tin oxide (ITO) conductive glass by a low-temperature liquid-phase deposition method and calcined by calcination treatment, and assembled into thin-film zinc-ion batteries (ZIBs). After galvanostatic charge/discharge (GCD) tests with 90 and 200 charge/discharge cycles, the ZIBs system provided specific capacities of 95.7 mAh m⁻² and 63.9 mAh m⁻² with capacity retention rates of 97.88% and 78.72%, respectively. The electrochemical reaction process of the Zn-doped V₂O₅ film electrode was analyzed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) to understand the insertion/extraction mechanism of Zn²⁺. The doping of appropriate amount of Zn²⁺ in the preparation plays the role of “pillar”, which helps to stabilize the structure of V₂O₅ and improve the cycling stability and lifetime. Therefore, the research may provide a new idea for the assembly and preparation of thin-film ZIBs with improved performance.

Bituminous coal, with its moderate anthracene content, high reactivity, and ease of modulation, stands out as a favorable choice as a precursor for hard carbon. However, due to the highly condensed aromatic rings in bituminous coal, it tends to form highly graphitized structures after high-temperature carbonization. Therefore, pretreatment of bituminous coal is necessary to suppress the graphitization process. Here, we combine pre-oxidation techniques with high-temperature carbonization to produce a cost-effective, high carbon yield, and superior performance coal-based hard carbon. When utilized as anode for sodium-ion batteries, the prepared coal-based hard carbon exhibits a high reversible capacity of 313.5 mAh g⁻¹, along with excellent rate capability and long cycling stability.

The Zebra (Na-NiCl₂) batteries are regarded as a promising option for large-scale electrical energy storage due to their plentiful electrode material resources, high energy density, and safety features. In the cathode of Zebra battery, the nickel powders serve as both an active material and a conductive agent. In practice, its amount is significantly greater than its theoretical usage, often exceeding three times the theoretical amount. Hence, the presence of ultra-excessive nickel results in high material costs, posing obstacles to the wider implementation of Zebra batteries. To address this problem, we introduce hollow nickel source as active material to improve the nickel utilization in Zebra battery. In this work, we assemble Zebra batteries using nickel hollow spheres (NHS) with sizes of ∼200 nm, ∼500 nm, ∼1 μm and ∼ 5 μm as nickel source. The battery using NHSs with a size of 1 μm exhibits the best cycling performance and the lowest polarization voltage. By reducing the Ni(NHS, ∼1 μm)/NaCl mass ratio to 1.0, 60% theoretical capacity can be achieved after 170 cycles at 260 °C, which surpasses the traditional batteries using solid nickel source at the same Ni/NaCl ratio. This performance is comparable to that of traditional solid nickel sources with a mass ratio of 1.5 to NaCl. Therefore, using NHS as the nickel source in Zebra batteries reduces nickel usage by 33% without compromising performance.

Electrolyte gelation is considered to be one of the main routes to solve the safety problem of liquid electrolytes. However, the distribution of gel polymer electrolyte (GPE) on the surface of electrodes and the mechanism of their effect on the performance of battery are still unknown. Here, methyl methacrylate (MMA) containing methyl (-CH₃) and methyl-2-cyanoacrylate (MCA) containing cyanide (-CN) are employed as representative monomers to explore the relationship between gel distribution and battery performance. Due to the stronger electron-withdrawing properties, PMCA gel has shorter chain length and greater shrinkage, showing many cracks on the electrode surface, while PMMA gel can evenly cover the surfaces of electrodes. As a result, the capacity retention rate of 1.4 Ah NCM811/Gr pouch cells with PMMA is 93.5% for 500 cycles at 25 °C and 91.5% for 600 cycles at 60 °C, which these of the cells with PMCA are 58.8% for 266 cycles at 25 °C and 69.1% for 327 cycles at 60 °C. XPS analysis of the electrode sheets before and after cycling reveal that the PMCA-electrode has a large number of rzero valent lithium element precipitation, whereas the PMMA-electrode has the more stable interface film. This study indicates that the uniform distribution of gel electrolyte with -CH₃ functional group on the electrode surface can improve the electrochemical performance of NCM811/Gr battery, which has the guiding significance.

Practical application of lithium‑sulfur batteries (LSBs) is severely impeded by the poor conductivity of sulfur/Li₂S, large-volume change of active materials, shuttle effect and sluggish conversion reaction kinetics of polysulfides. To address these issues, a three-dimensional (3D) substrate, which was prepared by anchoring CoO nanoarrays on the surface of nickel foam (NF@CoO) through one-step hydrothermal treatment, is used as the current collector of the sulfur cathode. The as-prepared S/NF@CoO cathode presents excellent electrochemical performances due to the high electronic conductivity of nickel network, chemical adsorption and catalysis of CoO nanoarrays to LiPSs, and highly porous structure of nickel foam. The cathode with a sulfur loading of 2.72 mg cm⁻² can deliver an initial capacity of 490 mAh g⁻¹ at 1C, and 306 mAh g⁻¹ after 500 cycles. When the sulfur loading is increased to 5.12 mg cm⁻², the resultant cathode can achieve a capacity of 2.3 mAh cm⁻² at 0.5C. The results demonstrate that the 3D NF@CoO collector with synergistic effects of catalysis and chemisorption on LiPSs enable the sulfur cathode thick with meeting the requirements of practical use of LSBs.

Metallic Sn is considered as a promising candidate of anode materials for lithium-ion batteries (LIBs) owing to its high capacity and ease of preparation. However, it undergoes severe mechanical damage after several lithiation/delithiation cycles due to the large volume change (∼300%). In this study, ultrafine Sn nanograins are embedded in N-doped amorphous carbon and then anchored onto reduced graphene oxide (rGO) via a facile one-pot synthesis route. The resulting composite consists of highly active Sn nanograins, three-dimensional carbon frameworks and highly conductive graphene oxide matrices. This unique configuration endows the composite with promising electrochemical performance. It delivers a reversible capacity of 1392 mAh g⁻¹ at a current density of 50 mA g⁻¹. When cycled after 300 times at 500 mA g⁻¹, it still maintains a reversible capacity of 805 mAh g⁻¹.

In this work, Mn₂O₃/Mn₃O₄ composites are prepared by a facile sucrose-assisted thermal decomposition method using MnCl₂·4H₂O, Mn(CH₃COO)₂·4H₂O, and MnSO₄·H₂O as manganese sources, respectively. The results demonstrate that manganese salt type has a significant influence on the morphology and phase composition of the final Mn₂O₃/Mn₃O₄ composites. The composites prepared from MnCl₂·4H₂O or Mn(CH₃COO)₂·4H₂O possess a porous sheet-like morphology, while the Mn₂O₃/Mn₃O₄ composite prepared from MnSO₄·H₂O has a much finer nanosheet morphology. The Mn₂O₃ contents in the composites prepared from MnCl₂·4H₂O, Mn(CH₃COO)₂·4H₂O, and MnSO₄·H₂O are about 57.8%, 95.0%, and 27.0%, respectively. Due to the differences in morphology and phase composition, the Mn₂O₃/Mn₃O₄ composites prepared from MnCl₂·4H₂O and Mn(CH₃COO)₂·4H₂O exhibit better zinc storage properties than the composite prepared from MnSO₄·H₂O. Among the three samples, the Mn₂O₃/Mn₃O₄ composite prepared from Mn(CH₃COO)₂·4H₂O shows superior zinc storage capability in short-term cycling and the best rate capability; the Mn₂O₃/Mn₃O₄ composite prepared from MnCl₂·4H₂O presents the best long-term cycling performance and moderate rate capability; the Mn₂O₃/Mn₃O₄ composite prepared from MnSO₄·H₂O displays the worst zinc storage capability and rate performance. EIS and CV analysis demonstrate that the Mn₂O₃/Mn₃O₄ composites prepared from MnCl₂·4H₂O or Mn(CH₃COO)₂·4H₂O have a low charge transfer resistance and obvious pseudocapacitive behavior during the charge/discharge process. The charge/discharge mechanism of the Mn₂O₃/Mn₃O₄ composites is also explored by ex-situ XRD characterization. This work provides a reference for the simple preparation of high-performance Mn₂O₃/Mn₃O₄ composites utilizing different manganese salts.

Solid oxide electrolysis cell (SOEC) is an efficient and environmentally friendly energy conversion device. The commercialization of SOEC is limited by the oxygen electrodes, whose problems include high costs and unexpected degradation of cobalt/strontium. In this study, we proposed a co-doping strategy and synthesized cobalt-free and strontium-free perovskite materials, specifically Ba_0.95Gd_0.05Fe_1-xCu_xO_3-δ (BGFCu_x), via the sol-gel method. These materials were evaluated as potential air electrodes for SOEC. The BGFCu_x samples were systematically characterized by crystal structure, oxygen content, thermal properties, electrical conductivity, and electrochemical performance. X-ray diffraction results show that the solid-solution concentration of Cu in BGFCu_x cannot exceed 0.1. X-ray photoelectron spectroscopy results suggest that Cu doping increases oxygen vacancy concentration. Among all BGFCu_x perovskites, BGFCu0.1 exhibited a low polarization resistance of 0.069 Ω·cm² at 800 °C (0.2 V) and a high current density of 216 mA·cm⁻² at an anodic bias of 40 mV. Hence, the Gd and Cu co-doped BGFCu0.1 perovskite material is a promising air electrode for SOEC.

Oxygen atom migration within solid oxides exerts a profound affects material properties, yet a rigorous conceptual framework for quantifying dynamic migration has been absent. To bridge this gap, we have developed a dynamic oxygen migration-release model, employing the differential element method with comprehensive mathematical proof. This novel model elucidates the exponential decay in the oxygen release rate of metal oxides as a function of the liberated oxygen quantity. We refined the model to discern between the migration of interior (bulk) oxygen and the reactions of oxygen at the surface, providing experimental validation for the energy barriers associated with each migration process. Taking CeO₂ as a case study, our model predicted and corroborated the energy barrier for oxygen release under various temperatures and morphologies, aligning with Density Functional Theory (DFT) analysis. Furthermore, the model's versatility is evidenced by its applicability to a wide range of metal oxides, including ceria-zirconia solid solutions, manganese oxide, and iron oxide, suggesting a broad potential for universal application. The unveiled dynamics of oxygen migration and release provide a theoretical foundation for refining the design of functional metal oxides and lay the groundwork for a more precise assessment of their oxygen reactivity.

In the present study, the electrochemical performance of the nickel (Ni)-foam electrodes (nano-confined-metal oxide composites: nc-SiO₂, nc-Al₂O₃, nc-MgO, nc-CaO) coated by electrodeposition via nano-confined lithium borohydride (nc-LiBH₄)-metal oxide (SiO₂, Al₂O₃, MgO, CaO) composites were investigated. Nano-confinement of LiBH₄ on metal-oxide structure approach was applied by a ball-milling process to prepare composites. The nc-metal oxide composites were electrodeposited on Ni foam using the chronoamperometry (CA) technique. The comparative study by cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) methods at different scan rates and current densities were used for electrochemical characterization of nc-metal oxide composites towards neat LiBH₄ and metal oxide. Cross-sectional analyses of scanning electron microscope elucidated that nc-CaO composite uniformly blankets the inner and outer surfaces of foam. These composites showed superior stability and reduced porosity in their surface structures, predominantly characterized by granular morphology and weak interparticle bonding, in contrast to other composite materials. Among CV curves, nc-CaO electrodeposited Ni foam electrode displayed a reduction of charge storage and lower capacitance values due to reduced porosity of nc-CaO composite towards LiBH₄ advanced in nano-confinement approach. Comparing specific capacitance of the electrodes first increased up to around 130 F/g and then decreased when metal oxides were added, while Ni electrodes prepared without nc-metal oxide composites showed an inverse relation with increasing current. The highest capacitance retention still after 2000 cycles achieved 85% stability.