DeCarbon最新文献

Lithium-ion batteries (LIBs) are indispensable as global energy production transitions to sustainable production. Nevertheless, the use of LIBs in renewable energy storage applications is challenging due to their limited power densities. To comprehend the origin of this limitation, it is crucial to investigate the effect of electrode architecture on the Li⁺ ion transport within their pores (solution-phase). In this work, the solution phase transport in various porous Li₄Ti₅O₁₂ (LTO) films was investigated using scanning ion conductance microscopy (SICM) and scanning electrochemical microscopy (SECM). When the porosity of LTO film increases, SECM and SICM approach curves show an increase in current. This is attributed to the ion transport through the film pores. The 2D topographical mapping using both techniques shows their ability to detect the LTO film's heterogeneity. Most importantly, this work gives insight into the complementary nature of the two scanning probe techniques as demonstrated by the comparable MacMullin numbers.

In this work manganese oxide (MnO₂) is modified with silico-tungstic acid (STA). Three samples are synthesized by the co-precipitation method. The powders obtained after elaboration are characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) imaging coupled to Electron Dispersive Spectroscopy (EDS) analysis and Brunauer-Emmet-Teller (BET) for their surface area determination. The effect of the modification of the manganese oxide with STA on its surface is determined. It is shown that MnO₂ modified with STA exhibits better cumulative high specific surface areas and mesoporous volumes areas. For example, the sample fabricates with 10% STA (MnO₂ – 10% STA) has a BET surface area of 153.6 ​m² ​g⁻¹ and volume area 0.92 ​cm³ ​g⁻¹ whereas the sample without STA (MnO₂ – 0% STA) has a surface area of 132.57 ​m² ​g⁻¹ and a mesoporous area of 0.26 ​cm³ ​g⁻¹. The electrochemical performance analysis of the different working electrodes prepared for super-capacitors applications is carried out using cyclic voltammetry (CV)., using a solution of 0.5 M K₂SO₄ as an electrolyte in potential range of −0.4 and 0.9 ​V at a sweep speed of 10 ​mV/s. The CV results are correlated to those of the BET surface and mesoporous areas values Accordingly, it is shown that samples spiked with STA exhibit higher electrochemical double layer capacitance than those of none modified with STA. These measurements respectively give 38 ​F ​g⁻¹, and 181 ​F ​g⁻¹ for MnO₂ without STA (MnO₂ – 0% STA), and MnO₂ modified with 10% STA (MnO₂ – 5% STA).

To tackle the increasing electromagnetic pollution, new and efficient electromagnetic wave absorption (EWA) and shielding (EWS) materials are urgently needed. Multi-component synergism and complex microstructure design are effective measures to improve the EWA and EWS properties. However, how to implement the above designs still faces huge challenges. Herein, multi-interface carbon-coated FeCoNi nanoneedles grown on carbon cloth (FeCoNi@C/CC) were synthesized by a combination of hydrothermal process and chemical vapor deposition (CVD) technology with the concept of “green synthesis”. Using acetylene as the carbon source and atmosphere, the FeCoNi ternary hydroxide can be transformed into a multiple magnetic component (Fe₃O₄, Ni, and Co metals) by simple annealing. Simultaneously, a uniform carbon layer is formed on the surface, resulting in a composite system with a variety of heterogeneous interfaces and loss mechanisms. Additionally, the dielectric and magnetic loss capacities can be effectively adjusted by changing the temperature of CVD. The optimized FeCoNi@C/CC as filler exhibits remarkable EWA performance with a minimum reflection loss of −69.3 ​dB at a thickness of 1.82 ​mm and a maximum effective absorption bandwidth of 6.80 ​GHz. Moreover, the composites as an integrated component also show a fascinating electromagnetic interference shielding efficiency of 42.2 ​dB. This work provides a guide for the structural design of high-performance electromagnetic protection materials with multi-heterogeneous interfaces.