Study on the extraction of dioscin by the ultrasonicassisted ethanol

With Dioscorea zingiberensis as row materials, and with the yield of diosgenin as assessment criteria, the effect on extraction yield of dioscin of frequency of ultrasonic, the period of ultrasonic and solidliquid ratio (D. zingiberensis : alcohol) was studied via orthogonal test. A new and unique method to accomplish this was by utilizing the technology of ultrasonic assisted ethanol extraction. The optimal processing parameters of this method were confirmed. The method was compared with solvent extraction process for the effect on extraction yield of dioscin. It was shown that the technology of ultrasonic assisted ethanol extraction which can significantly increase the extraction yield and extraction efficiency of dioscin. The ultrasonic did not destroy D. zingiberensis cell structure, but decreased the boundary layer thickness between D. zingiberensis (solid phase) and alcohol (medium), and accelerated cells inside and outside the material exchange. International rectifier (IR) further demonstrated that ultrasonic merely increased extraction yield of dioscin instead of destroying the cell structure.Keywords: D. zingiberensis, ultrasonic waves, extraction, diosgenin

Rectifying interphases for preventing Li dendrite propagation in solid-state electrolytes

Solid-state electrolytes have emerged as the grail for safe and energy-dense Li metal batteries but still face significant challenges of Li dendrite propagation and interfacial incompatibility. In this work, an interface engineering approach is applied to introduce an electronic rectifying interphase between the solid-state electrolyte and Li metal anode. The rectifying behaviour restrains electron infiltration into the electrolyte, resulting in effective dendrite reduction. This interphase consists of a p-Si/n-TiO2 junction and an external Al layer, created using a multi-step sputter deposition technique on the surface of garnet pellets. The electronic rectifying behaviour is investigated via the asymmetric I-V responses of on-chip devices and further confirmed via the one-order of magnitude lower current response by electronic conductivity measurements on the pellets. The Al layer contributes to interface compatibility, which is verified from the lithiophilic surface and reduced interfacial impedance. Electrochemical measurements via Li symmetric cells show a significantly improved lifetime from dozens of hours to over two months. The reduction of the Li dendrite propagation behaviour is observed through 3D reconstructed morphologies of the solid-state electrolyte by X-ray computed tomography

Photosensitisation of inkjet printed graphene with stable all-inorganic perovskite nanocrystals

All-inorganic perovskite nanocrystals (NCs) with enhanced environmental stability are of particular interest for optoelectronic applications. Here we report on the formulation of CsPbX3 (X is Br or I) inks for inkjet deposition and utilise these NCs as photosensitive layers in graphene photodetectors, including those based on single layer graphene (SLG) as well as inkjet-printed graphene (iGr) devices. The performance of these photodetectors strongly depends on the device structure, geometry and the fabrication process. We achieve a high photoresponsivity, R > 106 A W−1 in the visible wavelength range and a spectral response controlled by the halide content of the perovskite NC ink. By utilising perovskite NCs, iGr and gold nanoparticle inks, we demonstrate a fully inkjet-printed photodetector with R ≈ 20 A W−1, which is the highest value reported to date for this type of device. The performance of the perovskite/graphene photodetectors is explained by transfer of photo-generated charge carriers from the perovskite NCs into graphene and charge transport through the iGr network. The perovskite ink developed here enabled realisation of stable and sensitive graphene-based photon detectors. Compatibility of inkjet deposition with conventional Si-technologies and with flexible substrates combined with high degree of design freedom provided by inkjet deposition offers opportunities for partially and fully printed optoelectronic devices for applications ranging from electronics to environmental sciences

2020 roadmap on solid-state batteries

Li-ion batteries have revolutionized the portable electronics industry and empowered the electric vehicle (EV) revolution. Unfortunately, traditional Li-ion chemistry is approaching its physicochemical limit. The demand for higher density (longer range), high power (fast charging), and safer EVs has recently created a resurgence of interest in solid state batteries (SSB). Historically, research has focused on improving the ionic conductivity of solid electrolytes, yet ceramic solids now deliver sufficient ionic conductivity. The barriers lie within the interfaces between the electrolyte and the two electrodes, in the mechanical properties throughout the device, and in processing scalability. In 2017 the Faraday Institution, the UK's independent institute for electrochemical energy storage research, launched the SOLBAT (solid-state lithium metal anode battery) project, aimed at understanding the fundamental science underpinning the problems of SSBs, and recognising that the paucity of such understanding is the major barrier to progress. The purpose of this Roadmap is to present an overview of the fundamental challenges impeding the development of SSBs, the advances in science and technology necessary to understand the underlying science, and the multidisciplinary approach being taken by SOLBAT researchers in facing these challenges. It is our hope that this Roadmap will guide academia, industry, and funding agencies towards the further development of these batteries in the future