Xiong Zhang,Kangle Jia,Lei Zhang,Junjie Zhang,Yongqiang Dai,Longfei Yu,Wu Wen,Yuliang Mai
A series of green bio-based polyether surfactant were synthesized based on dehydroabietic acid and used to construct Pickering high internal phase emulsions (HIPEs) with microsilica particles which the dispersed phase fraction could up to 90%. Such surfactants have a high surface activity so that the Pickering HIPEs could be stabilized stably at low concentrations with micron-size silica . The microstructure, droplet size and rheology property of Pickering HIPEs could be regulated by varying the microsilica content or dispersed phase fraction. The QCM-D measurements revealed that the nonionic surfactant could adsorb on surface of silica particles, giving rise to the change of wettability of the hydrophilic particles and rendering the particles surface-active. The coated particles were more likely to adsorb at the oil-water interface of droplets. The synergistic effects of hydrophilic silica particles and this nonionic surfactant promoted the formation of stable Pickering HIPEs. Moreover, the depletion interaction between droplets and hydrophilic particles was also the vital factor in the stability of the Pickering HIPEs. Once particles were adsorbed, particles at the interface were inhibited desorption by depletion attraction. This work suggests another possible mechanism for better stability of Pickering HIPEs in nonionic surfactant/particles system, and our strategy to preparing Pickering HIPEs is environmentally friendly by using a bio-based surfactant, which has wide potential application in cosmetics, pharmaceuticals, food, environmental protection, materials, and so on.
Micro silicon (mSi) is a promising anode candidate for all-solid-state batteries due to its high specific capacity, low side reactions, and high tap density. However, silicon suffers from its poor electronic and ionic conductivity, which is particularly severe on a micro scale and in solid-state systems, leading to increased polarization and inferior electrochemical performance. Doping can broaden the transmission pathways and reduce the diffusion energy barrier for electrons and lithium ions. However, achieving effective, uniform doping in mSi is challenging due to its longer diffusion paths and higher energy barriers. Therefore, current doping research is primarily limited to nanosilicon. In this study, we successfully used a Joule-heating activated staged thermal treatment to achieve full-depth doping of germanium (Ge) in the mSi substrate. The Joule-heating process activated the mSi substrate, resulting in abundant vacancy defects that reduced the diffusion barrier of Ge into the silicon lattice and facilitated full-depth Ge doping. Surprisingly, the resulting Si-Ge anode exhibited significantly enhanced electrical conductivity (70 times). Meanwhile, the improved Li-ion conductivity in mSi and the reduced Young’s modulus enhance the electrode reaction kinetics and integrity after cycling. Ge-doped silicon anodes demonstrate excellent electrochemical performance when applied in sulfide solid-state half-cells and full-cells. This work provides substantial insights into the rational structural design of mSi alloyed anode materials, paving the way for the development of high-performance solid-state Li-ion batteries.
危险品化学品经营许可证（带存储）