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and environmental friendliness of the batteries. As a rare metal element, Li resources in the earth and their accessibility at low cost are a serious concern for upcoming larger-scale EES applications. Therefore, it is greatly needed to develop new batteries that are built up from environmentally benign and sustainable electrode materials. In the development of these new technologies, ambient sodium-ion batteries (SIBs) are revived and actively investigated as promising alternatives to LIBs for the next-generation energy storage devices due to the natural abundance of Na resources and the similar intercalation chemistry of Na + ions to their lithium counterpart. As a "rockingchair" type battery, the charge-discharge reactions of SIBs take place through a reversible Na + -intercalation mechanism, while Na ions move off from the cathode host, pass through the electrolyte and then insert into the anode host during charge, and vice versa during discharge. Meanwhile, electrons move from anode to cathode during charge or from cathode to anode during discharge through the external circuit, thus storing or delivering electric energy in a direct electrochemical manner.Studies on Na-intercalation chemistry can be dated back to the early 1980s, [ 2,3 ] almost in the same period as the development of Li-ion technology. Soon after the fi rst demonstration of lithium intercalation compounds for battery application, [4][5][6] the Na insertion behavior of Na x CoO 2 was also revealed as a cathode host. [ 7,8 ] Earlier pioneering works on earlier development of Na-ion technologies were given in a recent review. [ 9 ] Unfortunately, development of SIBs has almost halted in the past three decades since the successful commercialization of LIBs in the 1990s. A major reason for this embarrassment is the diffi culty to fi nd Na-host materials with comparable high capacities and suitable working potentials as their Li analogues. Because of larger atomic weight and less negative potential of Na than Li, Na-host materials have to suffer from a lower energy density than their Li counterparts. Furthermore, the larger ion radius of Na + (1.02 Å) than that of Li + (0.76 Å) make them kinetically frustrated during their insertion and transport in the host lattices, which further decreases the capacity utilization and rate performance of the materials.In recent years, great efforts have been made to achieve considerable success in understanding the Na + intercalation chemistry and in developing Na-host materials. It is now recognized that Na-host materials cannot simply be duplicated from their lithium analogues. For example, Okada and Sodium-ion batteries (SIBs) are now being actively developed as low cost and sustainable alternatives to lithium-ion batteries (LIBs) for large-scale electric energy storage applications. In recent years, various inorganic and organic Na compounds, mostly mimicked from their Li counterparts, have been synthesized and tested for SIBs, and some of them indeed demonstrate comparable specifi c capacity to the presentl...

An ultrasonic imaging technique has been developed to investigate the internal changes of pouch cells nondestructively. The local ultrasonic transmittance of pouch cells has been measured and used for imaging with a new ultrasonic scanning machine designed and built in-house. The wetting process of the cells is clearly observed via such ultrasonic imaging techniques. Furthermore, ultrasonic transmission images of fresh cells and aged cells with different electrolytes and cycling conditions exhibit very different ultrasonic transmittance, which can be caused by electrolyte dry-out or ''unwetting'' due to cell swelling. The ultrasonic imaging technique is a very sensitive method to probe failure mechanisms in Li-ion pouch cells.

Lithium‐ion batteries are the most commercially successful electrochemical devices, extensively used in intelligent electronics, electric vehicles, grid energy storages, etc. However, there still needs to be further improvement of their performance such as in energy density, cyclability, rate capability, and safety. To do so, it is necessary to understand the detailed structural evolution progress inside the battery. Many advanced imaging techniques have been developed to directly monitor the status and get some key information inside the battery. For advanced imaging techniques, superhigh resolution, fully informative function, nondestruction of the sample, and in situ observation are required. This review introduces and discusses some recent important progress on a variety of advanced imaging techniques for battery research. These imaging techniques have enabled the visualization of sub‐micrometer level chemical valence distribution, evolution of solid‐electrolyte interface, Li dendrite growth, and trace amount of gassing, etc., which greatly promote the development of rechargeable batteries. Of particular note, a new ultrasonic imaging technique has been recently developed to monitor gas generation, the electrolyte wetting process, and the state of charge in the battery. Finally, a perspective is given on some future developments in the imaging techniques for Li‐ion batteries and other rechargeable batteries.

Background:SKF83959 stimulates the phospholipase Cβ/inositol phosphate 3 pathway, resulting in the activation of Ca2+/calmodulin-dependent kinase IIα, which affects the synthesis of brain-derived neurotrophic factor, a neurotrophic factor critical for the pathophysiology of depression. Previous reports showed that SKF83959 elicited antidepressant activity in the forced swim test and tail suspension test as a novel triple reuptake inhibitor. However, there are no studies showing the effects of SKF83959 in a chronic stress model of depression and the role of phospholipase C/inositol phosphate 3/calmodulin-dependent kinase IIα/brain-derived neurotrophic factor pathway in SKF83959-mediated antidepressant effects.Methods:In this study, SKF83959 was firstly investigated in the chronic social defeat stress model of depression. The changes in hippocampal neurogenesis, dendrite spine density, and brain-derived neurotrophic factor signaling pathway after chronic social defeat stress and SKF83959 treatment were then investigated. Pharmacological inhibitors and small interfering RNA/short hairpin RNA methods were further used to explore the antidepressive mechanisms of SKF83959.Results:We found that SKF83959 produced antidepressant effects in the chronic social defeat stress model and also restored the chronic social defeat stress-induced decrease in hippocampal brain-derived neurotrophic factor signaling pathway, dendritic spine density, and neurogenesis. By using various inhibitors and siRNA/shRNA methods, we further demonstrated that the hippocampal dopamine D5 receptor, phospholipase C/inositol phosphate 3/ calmodulin-dependent kinase IIα pathway, and brain-derived neurotrophic factor system are all necessary for the SKF83959 effects.Conclusion:These results suggest that SKF83959 can be developed as a novel antidepressant and produces antidepressant effects via the hippocampal D5/ phospholipase C/inositol phosphate 3/calmodulin-dependent kinase IIα/brain-derived neurotrophic factor pathway.