Figure 1

Schematic illustration of the representative synchrotron-based techniques for investigating metal-air batteries. (color on line)

Figure 2

(A) Schematic of the diffraction process based on Bragg's law. Reproduced with permission of Ref.[30], copyright 2020 Wiley-VCH. (B) Synchrotron radiation XRD test device. Reproduced with permission of Ref.[37], copyright 2016 American Chemical Society. (C) Schematic diagram of in situ SXRD test and battery structure. Reproduced with permission of Ref.[38], copyright 2015 Nature Publishing Group. (color on line)

Figure 3

Schematic diagram showing the principle of multiple scattering of atoms and the spectroscopic features reflected in XAFS. Reproduced with permission of Ref.[41], copyright 2015 Science China Press and Springer-Verlag Berlin Heidelberg. (color on line)

Figure 4

Schematic diagram of full-field TXM and in situ cell structure. Reproduced with permission of Ref.[49], copyright 2015 Nature Publishing Group. (color on line)

Figure 5

(A) Sketch of SR X-ray CT experimental device; (B) In situ Li-air cell structure. Reproduced with permission of Ref.[58], copyright 2019 American Chemical Society. (color on line)

Table 1

Summary of synchrotron X-ray technology for metal-air cell research.

Figure 6

(A-D) Schematic cell configurations for different types of Li-air batteries. Reproduced with permission of Ref.[59], copyright 2017 Elsevier. (E) The reaction pathways in nonaqueous Li-air batteries. Reproduced with permission of Ref.[60], copyright 2020 Elsevier. (color on line)

Figure 7

(A) In situ synchrotron X-ray tomographic technique investigation of electrochemical and morphological of Li-metal anode. Reproduced with permission of Ref.[58], copyright 2019 American Chemical Society. (B) Synchrotron X-ray phase-contrast tomographic observation on morphological evolution of LMS. Reproduced with permission of Ref.[64], copyright 2016 American Chemical Society. (C) In situ synchrotron study of Li-air system under cycling process. Reproduced with permission of Ref.[38], copyright 2013 Nature Publishing Group. (color on line)

Figure 8

(A) Operando SXRD characterization of discharge product with LiBr as RMs. Reproduced with permission of Ref.[68], copyright 2021 American Chemical Society. (B) O K-edge XANES spectra and STXM images of the discharge products. Reproduced with permission of Ref.[69], copyright 2017 American Chemical Society. (C) STXM images of the discharge particles and average O K-edge XANES spectra of the same samples. Reproduced with permission of Ref.[70], copyright 2017 Elsevier. (color on line)

Figure 9

(A) In situ synchrotron XRD patterns and XANES of the Co@CoOx catalysts. Reproduced with permission of Ref.[74], copyright 2020 Wiley-VCH. (B) X-ray Nanocomputed Tomography in Zernike Phase Contrast of the cathode. Reproduced with per-mission of Ref.[76], copyright 2020 American Chemical Society. (C) STXM optical density images and the corresponding XANES spectra of C, Cl, and O distributions. Reproduced with permission of Ref.[77], copyright 2020 Elsevier. (D) STXM images of carbon-coated Au TEM grid after being fully discharged in a Li-air cell. Reproduced with permission of Ref.[78], copyright 2015 American Chemical Society. (color on line)

Figure 10

(A) Schematic diagram of a typical rechargeable non-aqueous Na-air battery. Reproduced with permission of Ref.[80], copyright 2018 Wiley-VCH. (B) Electronic configuration of the superoxide (top) and peroxide (bottom) anions. Reproduced with permission of Ref.[82], copyright 2018 American Chemical Society. (color on line)

Figure 11

(A) XAFS of CoO/CoP heterostructure (top two pictures) and in situ SXRD of discharge process (bottom two pictures). Reproduced with permission of Ref.[93], copyright 2018 American Chemical Society. (B) K-edge XANES of O and Na in TEY and FLY modes. Reproduced with permission of Ref.[95], copyright 2015 American Chemical Society. (C) SR X-ray CT with pure sodium metal (top three pictures) and Na@CC symmetric battery (top three pictures). Reproduced with permission of Ref.[96], copyright 2021 Elsevier. (color on line)

Figure 12

(A) O K-edge and N K-edge XAS of NCNT-PAN air electrode at different charge and discharge states. Reproduced with permission of Ref.[101], copyright 2019 Wiley-VCH. (B) FY and TEY modes of O K-edge XANES. Reproduced with permission of Ref.[102], copyright 2017 American Chemical Society. (C) Design drawing of Swagelok battery for synchrotron X-ray tomography. (D) The particle size distribution in the selected area inside the cathode is analyzed by CT. Reproduced with permission of Ref.[103], copyright 2016 Nature Publishing Group. (E) Absorbance image at 525.7 eV of a cubic discharge particle by STXM. (F) O K-edge XANES spectra of the Multivariate Curve Resolution (MCR) reconstructed components in the discharged particle. Reproduced with permission of Ref.[104], copyright 2017 Elsevier. (color on line)

Figure 13

(A) Schematic diagram of Zn-air battery with an aqueous alkaline electrolyte. (B) Schematic diagram of non-aqueous flexible Zn-air battery. Reproduced with permission of Ref.[105], copyright 2017 Wiley-VCH. (color on line)

Figure 14

(A) Integrated intensities of the red Zn (102) and black ZnO (002) reflections from battery Zn1 over time at different positions in the anode starting. Reproduced with permission of Ref.[112], copyright 2019 Elsevier. (B-C) SR X-ray CT of Zn dendrite growth with (B) or without (C) a separator. Reproduced with permission of Ref.[113], copyright 2019 Elsevier. (color on line)

Figure 15

(A) In situ SXRD in the discharge process of Zn/Zn-Bi2O3 anode. Reproduced with permission of Ref.[116], copyright 2018 Elsevier. (B) SEM and CT characterizations of the 3D interface in Asy-cathode. Reproduced with permission of Ref.[117], copyright 2020 Wiley-VCH. (color on line)

Figure 16

(A) K-edge XANES spectra and EXAFS of Co-POC. Reproduced with permission of Ref.[118], copyright 2019 Wiley-VCH. (B) Fe-N4 SAs/NPC. Reproduced with permission of Ref.[119], copyright 2018 Wiley-VCH. (C) (Fe, Co)/CNT. Reproduced with permission of Ref.[121], copyright 2018 Elsevier. (D) CoNi-SAs/NC. Reproduced with permission of Ref.[122], copyright 2019 Wiley-VCH. (color on line)