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The amount of global hybrid‐electric and all electric vehicle has increased dramatically in just five years and reached an all‐time high of over 10 million units in 2022. A good deal of waste lithium (Li)‐containing batteries from dead vehicles are invaluable unconventional resources with high usage of Li. However, the recycle of Li by green approaches is extremely inefficient and rare from waste batteries, giving rise to severe environmental pollutions and huge squandering of resources. Thus, in this mini review, we briefly summarized a green and promising route‐photoelectrochemical (PEC) technology for extracting the Li from the waste lithium‐containing batteries. This review first focuses on the critical factors of PEC performance, including light harvesting, charge‐carrier dynamics, and surface chemical reactions. Subsequently, the conventional and PEC technologies applying in the area of Li recovery processes are analyzed and discussed in depth, and the potential challenges and future perspective for rational and healthy development of PEC Li extraction are provided positively. [ABSTRACT FROM AUTHOR]

Owing to a large band gap and high surface energy determined via theoretical calculation, anatase TiO2 with dominant (211) facets can be expected to serve as one of the candidates for inorganic photoanode materials. Unfortunately, high-energy (211) surfaces containing four- and five-coordinated Ti atoms usually diminish rapidly during the crystal growth by a thermal process as a result of the minimization of surface energy. Here we report a successful preparation of an anatase TiO2 photoanode with dominant (211) facets on various substrates by magnetron sputtering technology. The proposed formation mechanism of (211) facets is derived from the competition between high-energy ion impinging and thermodynamics in the deposition process. The TiO2 photoanode with over 1 μm thickness yields a record charge-separation efficiency of ∼54.4% at 0.46 V versus the reversible hydrogen electrode, corresponding to a photocurrent density of ∼0.32 mA cm−2. The photogenerated charge carriers are directionally separated within the crystal grains by the internal magnetic field and quickly transported on the (211) surfaces with unsaturated coordination sites. Most importantly, we find that the photoanode simultaneously integrates flexible, hard and lubricant effects into photoelectrochemical behaviors, leading to long-term stable operation (over 1100 h), good durability with a low wear rate, and facile bendability (similar performance before and after bending). We also fabricate a large-area (10 × 10 cm2) photoanode and use it in an unbiased photoelectrochemical device, further suggesting its scaling and practical potential. [ABSTRACT FROM AUTHOR]

For the fixed-time nonlinear system control problem, a new fixed-time stability (FxTS) theorem and an integral sliding mode surface are proposed to balance the control speed and energy consumption. We discuss the existing fixed time inequalities and set up less conservative inequalities to study the FxTS theorem. The new inequality differs from other existing inequalities in that the parameter settings are more flexible. Under different parameter settings, the exact upper bound on settling time in four cases is discussed. Based on the stability theorem, a new integral sliding mode surface and sliding mode controller are proposed. The new control algorithm is successfully applied to the fixed-time control of chaotic four-dimensional Lorenz systems and permanent magnet synchronous motor systems. By comparing the numerical simulation results of this paper's method and traditional fixed-time sliding mode control (SMC), the flexibility and superiority of the theory proposed in this paper are demonstrated. Under the same parameter settings, compared to the traditional FxTS SMC, it reduces the convergence time by 18%, and the estimated upper bound of the fixed time reduction in waiting time is 41%. In addition, changing the variable parameters can improve the convergence velocity. [ABSTRACT FROM AUTHOR]

Photoelectrochemical lithium (Li) extraction can be expected to provide a useful recycle of Li+ from waste Li‐containing battery, but the process is limited by the photocathodes with poor Li+ absorption and low yield rate. Here, we have designed a hierarchical silicon (Si)‐based photocathode with mixed‐phase tungsten oxide (WO3) cocatalysts for photoelectrochemical Li extraction under 1 sun illumination, achieving a high Li yield rate of ≈223.0 μg cm−2 h−1 and an excellent faradaic efficiency of 91.9 % at 0.0817 V versus Li0/+ redox couple. The WO3 cocatalysts with the mixture of amorphous and crystalline phase accelerates the Li+ insertion and precipitation and enriches the concentration of Li+ at the photocathode surface. This robust photoelectrochemical Li extraction system provides a new insight on designing green and efficient route for cyclic utilization of Li resources in the sustainable energy field. [ABSTRACT FROM AUTHOR]

Control of the structural, mechanical and tribological properties of TiCN films play an important role in its numerous applications, including the cutting tools, mechanical components, aeronautical and biomedical engineering industries. Direct-current magnetron sputtering (DCMS) system was applied to deposit TiCN films onto n-type silicon (100) at room temperature. The Ti-TiN interlayer was used to enhance the adhesive strength between the coating and the substrate. The composition and microstructure of the TiCN films were studied using X-ray photoelectron spectroscopy (XPS) and field-emitted scanning electron microscopy (FESEM). The mechanical properties of the films as a function of methane (CH4) flow ratio were then characterized using nano-indentation measurements. The tribological behavior of TiCN films was investigated by UMT-2MT tribometer against a Si3N4 ceramic and AISI52100 steel ball. After the tribological tests, the wear rate of the films was obtained by the 3D surface profiler and the component content of wear debris was evaluated by energy dispersive X-ray spectroscopy (EDS). The results show that the tribological properties of TiCN films are a function of CH4 flow rates. The film obtained at a 10 sccm CH4 flow rate possesses a minimum average COF value of 0.1964 and reaches 72,000 cycles against a Si3N4 ball over the test duration. Furthermore, the wear rate was only 2.076 × 10−6 mm3/N·m. Furthermore, the TiCN films exhibited longer lifespan against the Si3N4 ball than against the steel ball under the normal load of 1 N, indicating that the TiCN films present better lubricative properties when against low-hardness counterparts than high-hardness counterparts. [ABSTRACT FROM AUTHOR]