Search Results (5)

All-solid-state lithium-ion batteries (ASSLBs) are attractive energy storage devices because of their excellent gravimetric and volumetric capacity and ability to supply high power rates. Porous silicon (Si) is a promising material for an anode in lithium-ion batteries due to its high capacity and low discharge potential. However, Si anodes cause significant problems due to strong volume growth during the lithiation and delithiation processes, which results in rapid capacity fading and poor cycle stability. To overcome this problem, we developed mesoporous silica (SiO₂) aerogels into porous silicon (Si) anodes using a magnesiothermic reduction (MTR) process. By effectively preserving the porous structure, this approach enables the material to endure volume fluctuations while maintaining its structural integrity during cycling. In our study, we demonstrated a feasible approach to fabricate the porous silicon (Si) from hydrophobic and hydrophilic silica (SiO₂) aerogel and magnesium powder (Mg) through the MTR process at 600~900 °C. The sample obtained after the reduction process was treated with hydrochloric acid (HCl) to remove byproducts. As prepared, Si was characterized using various techniques, including XRD, XRF, FT-IR, XPS, SEM, and BET, which confirmed the successful production, chemical purity, and structural retention of Si. Furthermore, the coin cell was fabricated using Si as an anode, and the electrochemical performance was analyzed. The charge/discharge cycling tests at 1 C and 0.02~2 V (vs. the Li condition) revealed the effects of silicon content, wettability, and interfacial compatibility on electrode performance. Conversely, for better understanding, a long-term cycling test was conducted at 1 C rate, 0–1.5 V (vs. Li) to evaluate capacity retention. Our findings highlight the potential application of silicon (Si) aerogels produced from silica (SiO₂) aerogels by magnesiothermic reduction to improve lithium-ion battery performance. Full article

For all-solid-state batteries, the particle size distribution of the solid electrolyte is a critical factor. Small particles are preferred to obtain a high active mass loading of cathode active material and a small porosity in composite cathodes. In this work, the influence of the solid fraction in the wet-chemical synthesis of β-Li₃PS₄ in tetrahydrofuran (THF) is investigated. The solid fraction is varied between 50 and 200 mg/mL, and the obtained samples are evaluated using X-ray diffraction, SEM and electrochemical impedance measurements. The sizes of the resulting particles show a significant dependency on the solid fraction, while a good ionic conductivity is maintained. For the highest concentration, the particle sizes do not exceed 10 µm, but for the lowest concentration, particles up to ~73 µm can be found. The ionic conductivities at room temperature are determined to be 0.63 ± 0.01 × 10⁻⁴ S/cm and 0.78 ± 0.01 × 10⁻⁴ S/cm for the highest and lowest concentrations, respectively. These findings lead to an improvement towards the production of tailored sulfide solid electrolytes. Full article

Current Li battery technology employs graphite anode and flammable organic liquid electrolytes. Thus, the current Li battery is always facing the problems of low energy density and safety. Additionally, the sustainable supply of Li due to the scarce abundance of Li sources is another problem. An all-solid-state Mg battery is expected to solve the problems owing to non-flammable solid-state electrolytes, high capacity/safety of divalent Mg metal anode and high abundance of Mg sources; therefore, solid-state electrolytes and all-solid-state Mg batteries have been researched intensively last two decades. However, the realization of all-solid-state Mg batteries is still far off. In this article, we review the recent research progress on all-solid-state Mg batteries so that researchers can pursue recent research trends of an all-solid-state Mg battery. At first, the solid-state electrolyte research is described briefly in the categories of inorganic, organic and inorganic/organic composite electrolytes. After that, the recent research progress of all-solid-state Mg batteries is summarized and analyzed. To help readers, we tabulate electrode materials, experimental conditions and performances of an all-solid-state Mg battery so that the readers can find the necessary information at a glance. In the last, challenges to realize the all-solid-state Mg batteries are visited. Full article

About 25 years ago, Bogdanovic and Schwickardi (B. Bogdanovic, M. Schwickardi: J. Alloys Compd. 1–9, 253 (1997) discovered the catalyzed release of hydrogen from NaAlH₄. This discovery stimulated a vast research effort on light hydrides as hydrogen storage materials, in particular boron hydrogen compounds. Mg(BH₄)₂, with a hydrogen content of 14.9 wt %, has been extensively studied, and recent results shed new light on intermediate species formed during dehydrogenation. The chemistry of B₃H₈⁻, which is an important intermediate between BH₄⁻ and B₁₂H₁₂²⁻, is presented in detail. The discovery of high ionic conductivity in the high-temperature phases of LiBH₄ and Na₂B₁₂H₁₂ opened a new research direction. The high chemical and electrochemical stability of closo-hydroborates has stimulated new research for their applications in batteries. Very recently, an all-solid-state 4 V Na battery prototype using a Na₄(CB₁₁H₁₂)₂(B₁₂H₁₂) solid electrolyte has been demonstrated. In this review, we present the current knowledge of possible reaction pathways involved in the successive hydrogen release reactions from BH₄⁻ to B₁₂H₁₂²⁻, and a discussion of relevant necessary properties for high-ionic-conduction materials. Full article

Hydrogen as an energy carrier is very versatile in energy storage applications. Developments in novel, sustainable technologies towards a CO₂-free society are needed and the exploration of all-solid-state batteries (ASSBs) as well as solid-state hydrogen storage applications based on metal hydrides can provide solutions for such technologies. However, there are still many technical challenges for both hydrogen storage material and ASSBs related to designing low-cost materials with low-environmental impact. The current materials considered for all-solid-state batteries should have high conductivities for Na⁺, Mg²⁺ and Ca²⁺, while Al³⁺-based compounds are often marginalised due to the lack of suitable electrode and electrolyte materials. In hydrogen storage materials, the sluggish kinetic behaviour of solid-state hydride materials is one of the key constraints that limit their practical uses. Therefore, it is necessary to overcome the kinetic issues of hydride materials before discussing and considering them on the system level. This review summarizes the achievements of the Marie Skłodowska-Curie Actions (MSCA) innovative training network (ITN) ECOSTORE, the aim of which was the investigation of different aspects of (complex) metal hydride materials. Advances in battery and hydrogen storage materials for the efficient and compact storage of renewable energy production are discussed. Full article