A review on wear-resistant coating with high hardness and high toughness on the surface of titanium alloy

The primary task of a battery is to store energy and to power electronic devices. This has hardly changed over the years despite all the progress made in improving their electrochemical performance. In comparison to batteries, electronic devices are continuously equipped with new functions, and they also change their physical appearance, becoming flexible, rollable, stretchable, or maybe transparent or even transient or degradable. Mechanical flexibility makes them attractive for wearable electronics or for electronic paper; transparency is desired for transparent screens or smart windows, and degradability or transient properties have the potential to reduce electronic waste. For fully integrated and self-sufficient systems, these devices have to be powered by batteries with similar physical characteristics. To make the currently used rigid and heavy batteries flexible, transparent, and degradable, the whole battery architecture including active materials, current collectors, electrolyte/separator, and packaging has to be redesigned. This requires a fundamental paradigm change in battery research, moving away from exclusively addressing the electrochemical aspects toward an interdisciplinary approach involving chemists, materials scientists, and engineers. This Outlook provides an overview of the different activities in the field of flexible, transient, and transparent batteries with a focus on the challenges that have to be faced toward the development of such multifunctional energy storage devices.

Multifunctional Batteries: Flexible, Transient, and Transparent

Review—Corrosion-Resistant High-Entropy Alloy Coatings: A Review

Electrochromism: An emerging and promising approach in (bio)sensing technology

There is a growing worldwide demand in developing lithium ion batteries with high energy densities and longer cycle life. In recent years, rechargeable lithium ion batteries have become important alternative...

Nano structured silicon and silicon based composites as anode materials for lithium ion batteries: recent progress and perspectives

Modulation of Si on microstructure and tribo-mechanical properties of hydrogen-free DLC films prepared by magnetron sputtering

Microstructure effects on fracture failure mechanism of CrAl/CrAlN coating

To solve the issue of elemental interdiffusion between protective coating and superalloy substrate during high-temperature service, an AlCoCrNiMo high-entropy alloy (HEA) diffusion barrier was deposited by direct current magnetron sputtering between NiAlHf protective coating and Ni-based single crystal superalloy (Rene N5). The interdiffusion behavior and high-temperature oxidation resistance of the coating system were investigated via isothermal oxidation at 1373 K. After long-term oxidation at 1373 K, no interdiffusion zone (IDZ), secondary reaction zone (SRZ) and rod/needle-like topologically close-packed (TCP) precipitates were observed in the coating system with HEA diffusion barrier. Besides, the NiAlHf coating exhibited an improved oxidation resistance with the addition of HEA diffusion barrier. The results indicate that the HEA diffusion barrier can suppress the interdiffusion of alloying elements between substrate and coating effectively, which is attributed to the sluggish diffusion effect of HEA and the in-suit formed alumina layers at the substrate/HEA and HEA/NiAlHf interfaces during high-temperature oxidation. Moreover, it was found that the Co element in HEA layer also plays an important role in suppressing the formation of SRZ and TCP precipitates in the superalloy.

AlCoCrNiMo high-entropy alloy as diffusion barrier between NiAlHf coating and Ni-based single crystal superalloy

Al-doped ZnO (AZO) films were deposited by mid-frequency (MF) sputtering technique as transparent anode materials for Li-ion batteries. The optoelectric and electrochemical behavior of the AZO film were investigated. The high transmittance of 84% in visible range and low electrical resistivity of 7.67 × 10−4 Ω·cm were obtained at sputtering pressure of 0.1 Pa. As a promising anode, the AZO films exhibit high specific capacity of 301 mA h/g. The results reveal that the resistivity of film had great influence on its electrochemical performance. A stable cycling retention was observed due to improved electric conductivity. However, the transparency of AZO film varied to 50% when recharged to 2.5 V, indicating the bleached and colored properties during lithiation/delithiation process. Those characteristics make it a potential candidate for electrochromic devices.

Electrochemical and optoelectric behavior of Al-doped ZnO films as transparent anode for Li-ion batteries

In arc-ion plating, the droplets ejected from the cathodic target inevitably contaminate the coating with macro-particles (MPs), causing defects that usually reduce the mechanical properties of the...

Chao-Qian Guo

Papers

Modulation of Si on microstructure and tribo-mechanical properties of hydrogen-free DLC films prepared by magnetron sputtering

Microstructure effects on fracture failure mechanism of CrAl/CrAlN coating

AlCoCrNiMo high-entropy alloy as diffusion barrier between NiAlHf coating and Ni-based single crystal superalloy

Electrochemical and optoelectric behavior of Al-doped ZnO films as transparent anode for Li-ion batteries

Effect of electromagnetic voltage on wear resistance of CrAlN coatings