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High entropy alloy compound film is a two-dimensional material prepared based on the design idea of multi-principal element high entropy alloys. In addition to its metal elements， non-metallic elements such as C， N and O are added to form strong metal-nonmetal covalent bonds in the film，making the film present many excellent properties which have attracted widespread attention. In this paper， the development history of high entropy alloy compound films was summarized， and the main preparation methods and structural characteristics of high entropy alloy compound films were introduced. Besides， the research status of their mechanical properties， thermal stability， wear resistance and corrosion resistance was analyzed emphatically. Finally， the potential applications and development trends of high entropy alloy compound films were pointed out.

Lithium metal anode is one of the ideal anodes with high energy density. However, the problems of lithium dendrite growth and infinite volume expansion lead to safety and cycling stability problems in lithium metal anode batteries, which became the biggest obstacle to the commercial application of lithium metal anodes. This paper reports a three-dimensional nanostructured TiO2 flexible lithium metal anode scaffold loaded with Sn. Three-dimensional nanostructured TiO2 has a high specific surface area that can accommodate lithium deposition with high capacity while suppressing lithium dendrite growth. At a current density of 1 mA cm−2 and a deposition volume of 5 mAh cm−2, the 35th circulate coulomb efficiency of the lithium metal anode scaffold is still 98%. The nano-Sn metal with better pro-lithium properties loaded on the lithium metal anode scaffold composed of TiO2 skeleton, which can sufficiently reduce the nucleation potential barrier of Li+ and enable the uniform deposition of lithium on the support, assembled into a full coin cell using a LiFeO4 (LFP)-based positive electrode exhibit high-capacity retention and high energy density (443 Wh kg−1) after 200 cycles at 1C (= 170 mA g−1). [ABSTRACT FROM AUTHOR]

Combustible gas concentration detection faces challenges of increasing accuracy, and sensitivity, as well as high reliability in harsh using environments. The special design of the optical path structure of the sensitive element provides an opportunity to improve combustible gas concentration detection. In this study, the optical path structure of the sensitive element was newly designed based on the Pyramidal beam splitter matrix. The infrared light source was modulated by multi-frequency point signal superimposed modulation technology. At the same time, concentration detection results and confidence levels were calculated using the 4-channel combustible gas concentration detection algorithm based on spectral refinement. Through experiment, it is found that the sensor enables full-range measurement of CH4, at the lower explosive limit (LEL, CH4 LEL of 5%), the reliability level is 0.01 parts-per-million (PPM), and the sensor sensitivity is up to 0.5PPM. The sensor is still capable of achieving PPM-level detections, under extreme conditions in which the sensor's optical window is covered by 2/3, and humidity is 85% or dust concentration is 100mg/m3. Those improve the sensitivity, robustness, reliability, and accuracy of the sensor. [ABSTRACT FROM AUTHOR]

This paper proposes the preparation of a S-Se-Ti3C2Tx/TiO2 cathode by etching Ti3AlC2 with hydrofluoric acid and doping with selenium (Se). Through an electrochemical performance test, selenium is doped into the active material sulfur and forms a sulfur-selenium compound to compensate for the 'chemical inertness' of the elemental sulfur, thereby increasing the utilization rate of the active material. Taking advantage of the ability of TiO2 to absorb polysulfide compounds and the high conductivity of carbides, the Ti3C2Tx composite material, modified with TiO2 nanodots, is constructed in situ as a sulfur-selenium composite material carrier, achieving a high sulfur content of 80%. S-Se-Ti3C2Tx/TiO2 is used as the cathode, and the initial discharge specific capacity is as high as 1073 mAh g−1, which improves the utilization of active materials and effectively inhibits the shuttle effect of lithium polysulfide intermediates. [ABSTRACT FROM AUTHOR]