In situ scanning electron microscopy (SEM) offers a good way to investigate the structural evolution during lithiation and delithiation processes. In this paper, the dynamical morphological evolution of 3D-line-structured/unstructured Si/C composite electrodes was observed by in situ SEM. The investigation revealed the microstructural origin of large charge capacity for 3D-line-structured anodes. Based on this proposed mechanism, a coarse optimization of 3D-line-structured anodes was proposed. These results shed light on the unique advantages of using an in situ SEM technique when studying realistic bulk batteries and designing 3D electrode structures.

The novel hierarchical Ni-Co sulfide nanosheet-nanotubes arrays were directly grown on Ni foam, as binder-free electrodes, have been successfully synthesized following a one-step facile hydrothermal method combined with a sulfide treatment. The initial value of the area capacitance achieved 2.28 F cm⁻² at a current density of 1 mA cm⁻². A high areal capacitance retention of 95.2% compared to activation-induced peak value is achieved after 3000 charge-discharge cycles, which is much better than counter Ni-Co oxide electrode (1.75 F cm⁻² at 1 mA cm⁻², 93.2% retention compared to activation induced peak value). The outstanding and excellent super capacitive performance is ascribed to ion-exchange reaction, which induces a flexible hollow nanotube feature and show higher conductivity, compared with Ni-Co oxide NWs. Cyclic voltammetry (CV) and Electrochemical impedance spectra (EIS) results confirmed that the synthesized electrode contains the lowest resistance at high, and at lower frequency, leading to easy penetration of electrolytes and fast transportation of electrons inside the electrode. In this proposed work, a one-step hydrothermal method has been followed, and provided for the sulfide-induced, with a noticeable electrochemical performance of nickel cobaltite compounds and supplying a promising route for high-performance supercapacitor electrodes.

Garnet-type solid electrolytes have gained considerable attention owing to their exceptional ionic conductivity and broad electrochemical stability window, making them highly promising for solid-state batteries (SSBs). However, this polycrystalline ceramic electrolyte contains an abundance of grain boundaries (GBs). During the repetitive electroplating and stripping of Li ions, uncontrolled growth and spreading of lithium dendrites often occur at GBs, posing safety concerns and resulting in a shortened cycle life. Reducing the formation and growth of lithium dendrites can be achieved by rational grain boundary design. Herein, the garnet-type solid electrolyte LLZTO was firstly coated with Al₂O₃ using the atomic layer deposition (ALD) technique. Subsequently, an annealing treatment was employed to introduce Al₂O₃ into grain boundaries, effectively modifying them. Compared with the Li/LLZTO/Li cells, the Li/LLZTO@Al₂O₃-annealed/Li symmetric batteries exhibit a more stable cycling performance with an extended period of 200 h at 1 mA cm⁻². After matching with the NMC811 cathode, the capacity retention rate of batteries can reach 96.8% after 50 cycles. The infusion of Al₂O₃ demonstrates its capability to react with LLZTO particles, creating an ion-conducting interfacial layer of Li-Al-O at the GBs. This interfacial layer effectively inhibits Li nucleation and filament growth within LLZTO, contributing to the suppression of lithium dendrites. Our work provides new suggestions for optimizing the synthesis of solid-state electrolytes, which can help facilitate the commercial application of solid-state batteries.

In order to clarify the deformation mechanism of Inconel 718 (IN718) alloy at the grain scale during tensile deformation, the deformation behaviors of IN718 alloy were investigated at 650 °C using an in situ electron backscatter diffraction (EBSD) tensile testing method. The evolution of grain morphology, crystallographic orientation, activated slip systems, grain boundaries evolution, and strain-induced misorientation were systematically analyzed during the tensile test. The results showed that the grains were elongated along the tensile direction, and the grain boundaries also became significantly curved. Meanwhile, the EBSD studies illustrated that the changes in local misorientation within individual grains were non-uniform and generally began at the grain boundaries. The low-angle grain boundaries (LAGBs) were first formed near the high-angle grain boundaries (HAGBs) and gradually expanded into the interior of the grains. The activation of the slip system and the Schmid factor were characterized and calculated based on the slip traces on the deformed grain surface. The evolution of local strain within the grains was evidenced by a kernel average misorientation (KAM) map. Finally, the plastic deformation mechanism at the grain scale was discussed in detail based on our experimental results.