Recent progress of in-situ/operando characterization approaches of zinc-air batteries

Zinc-air batteries (ZABs) belong to the category of metal-air batteries, with high theoretical energy density, safety, and low cost. Nevertheless, there are still many challenges that need to be solved for the practical application of ZABs, including high overpotential, poor cycle life, and so on. This article first briefly introduced the principle of ZABs, covering the key components, functions of each element, and challenges faced by the system. Subsequently, seven methods for studying ZABs in-situ or operando were introduced, including X-ray computed tomography (XCT), optical microscopy imaging (OMI), transmission electron microscopy, nuclear magnetic resonance imaging (MRI), X-ray diffraction (XRD), Raman spectroscopy, and X-ray absorption spectroscopy, accompanied by specific research examples. The future perspectives of ZAB characterization have also been discussed.