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Silica-supported nanostructured copper phyllosilicate: Boosting stability, capacity, and conductivity of Li-ion battery Si-based anodes
(2026-11-01)
Shajan, Minnu Gemini
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Chou, Feng Yuan
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Prasanseang, Warot
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Yimtrakarn, Trakarn
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Sooknoi, Tawan
Explosive demand for large-scale rechargeable batteries has driven the search for alternative electrode materials with higher energy density, lower toxicity, lower cost, and more natural abundance. Si-based materials, e.g., Si, SiO, SiO<inf>2</inf>, and silicates have emerged as promising choices, with extremely high capacities from most cost-effective and abundant sources. However, these compounds still suffer from major issues, such as extreme volume change, poor cycling stability, high manufacturing costs, and low conductivity. Herein, we have prepared low-cost porous nanosized silica-supported copper phyllosilicate, x CuPS/SiO<inf>2</inf>, with different Cu loadings and investigated them as anode material in Li cells. Due to the highly dispersed Cu species strongly interacted with nanosphere SiO<inf>2</inf> support matrix, 20CuPS/SiO<inf>2</inf> has been found to deliver a capacity as high as ∼3550 mAh g‒1 at 500 mA g‒1 with an impressive capacity retention of 99% upon conversion reactions with Li+, and a reversible capacity of 2216 mAh g‒1 at 5000 mA g‒1. These values are among the highest ever reported for Si-, silicate-, silica-, and copper oxide-based anodes. Various phases, i.e., CuO, Li<inf>4</inf>SiO<inf>4</inf>, SiO, Si, Li<inf>2</inf>O, Cu, and Li<inf>x</inf>Si, are formed in the SiO<inf>2</inf> nanodomain, as confirmed by various ex situ characterization techniques, and the redox mechanism has been proposed. The components, particularly Li<inf>4</inf>SiO<inf>4</inf>, Li<inf>2</inf>O, and SiO<inf>2</inf>, are shown to help buffer volumetric or structural changes induced by the redox processes. The nanosized composite and the in situ -formed metallic Cu play a crucial role in rapid charge-transfer kinetics. These synergistic effects ultimately result in an unprecedented electrochemical performance of x CuPS/SiO<inf>2</inf> observed in this work.
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Mn-Fe Prussian blue analogue as low-cost robust cathode for non-aqueous Zn-ion batteries
(2023-03-01)
Yimtrakarn, Trakarn
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Liao, Yi Chih
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MV, Ahmed Sanin
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Chen, Jeng Lung
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Chuang, Yu Chun
Zn-ion batteries (ZIBs) are one of the most promising alternatives for large-scale energy storage systems due to two-electron transfer capability, safety, low toxicity, and low cost. However, most of the cathode materials reported for non-aqueous ZIBs still show unsatisfactory electrochemical performance. To overcome this, factors such as type of crystal structure, transition metal-ion coordination, and nature of the d orbitals being filled must be taken into consideration in the design of suitable host materials. Herein, we report the use of a Prussian blue analogue, sodium manganese hexacyanoferrate (NaMnFe-PB), as cathode in ZIBs. Its ease of synthesis, rigid open framework, and compositional and electrochemical tunability make this low-cost Mn-Fe-based compound highly attractive. The strong interactions among the two redox centers MnIII/MnII, FeIII/FeII, and C[tbnd]N- ligand allow two close voltage plateaus at ∼1.50 V vs Zn/Zn2+, delivering a capacity of 89.5 mAh g-1. Ex-situ X-ray absorption and diffraction techniques confirm the high redox reversibility and structural stability of NaMnFe-PB upon divalent guest insertion. The Fe(CN)<inf>6</inf> vacancies and coordinated water in the host lattice are believed to facilitate cation diffusion. The insight gained in this work may pave the way for the design of low-cost cathode materials for next-generation large-scale energy storage systems.
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Study of Lignin Extracted from Rubberwood Using Microwave Assisted Technology for Fuel Additive
(2022-02-01)
Yimtrakarn, Trakarn
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Kaveevivitchai, Watchareeya
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Lee, Wen Chien
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Lerkkasemsan, Nuttapol
Lignin is the most abundant natural aromatic polymer, especially in plant biomass. Lignin-derived phenolic compounds can be processed into high-value liquid fuel. This study aimed to determine the yield of lignin by the microwave-assisted solvent extraction method and to characterize some essential properties of the extracted lignin. Rubberwood sawdust (Hevea brasiliensis) was extracted for lignin with an organic-based solvent, either ethanol or isopropanol, in a microwave oven operating at 2450 MHz. Two levels of power of microwave, 100 W and 200 W, were tested as well as five extraction times (5, 10, 15, 20, 25, and 30 min). The extracted lignin was characterized by Klason lignin, Fourier transform infrared spectroscopy (FT-IR), 2D HSQC NMR, Ultraviolet-visible spectrophotometry (UV-vis), and Bomb calorimeter. The results showed that the yield of extracted lignin increased with the extraction time and power of the microwave. In addition, the extraction yield with ethanol was higher than the yield with isopropanol. The highest yield was 6.26 wt.%, with ethanol, 30 min extraction time, and 200 W microwave power.

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