Coupling Engineering of NH₄⁺ Pre‐Intercalation and Rich Oxygen Vacancies in Tunnel WO₃ Toward Fast and Stable Rocking Chair Zinc‐Ion Battery

Abstract

Keywordsethylene glycol additive aqueous electrolytes, intercalated anodes, oxygen defects, rocking-chair zinc-ion batteries (ZIBs), Zn-(NH 4 ) x WO 3 batteries

Three‐Dimensional Ordered Macroporous Amorphous WO3 Arrays for Zinc‐Based Electrochromic Device with Large Light Modulation and Fast Switching

“…For the O 1s spectrum in Figure 1j, three peaks are observed at 530.50, 531.15, and 532.50 eV in a-WO 3 -IO, which can be assigned to the W─O bonds, oxygen defects and the adsorbed oxygen, respectively, further confirming that a number of oxygen vacancies exist in a-WO 3 -IO. [25] While in crystalline 𝛾-WO 3 -IO, only two peaks related to lattice oxygen associated with W─O bonds and adsorbed oxygen can be observed, [25,28] which is consistent to the results in W XPS spectra. Furthermore, the oxygen vacancies can be identified by the electron paramagnetic resonance (EPR) analysis (Figure S4, Supporting Information), wherein the EPR signal suggests the unpaired electrons trapped on surface oxygen vacancies.…”

“…For the a-WO 3 -IO, three peaks can be fitted from the two W 4f peaks (Figure 1i), that is, two strong peaks at 35.85 and 37.98 eV, corresponding to the W 4f 7/2 and W 4f 5/2 of W 6+ , and a small peak at 36.82 eV, corresponding to the W 4f 5/2 of W 5+ . [24,25] The co-existence of two valence states of tungsten indicates abundant oxygen vacancies in a-WO 3 -IO, which would facilitate the insertion and extraction of Zn ions. [26,27] However, the peak related to W 4f 5/2 of W 5+ disappear in 𝛾-WO 3 -IO, due to the absence of oxygen vacancies.…”

“…Another pair of peaks, centered at 34.10 and 36.82 eV, correspond to the W 5+ . [24,25] The amount of W 6+ state decreases accompanied by the substantial increases of W 5+ state upon discharging. The atomic ratio of W 5+ /W 6+ for the bleached a-WO 3 -IO is estimated to be 0.09.…”

Oxygen Vacancy-Enriched Bi2SeO5 Nanosheets with Dual Mechanism for Ammonium-Ion Batteries

“…After discharging to −1.3 V, its intensity increased obviously and decreased when charging to 0.3 V, proving the reversible insertion and extraction of NH 4 + . In particular, the increase of −NH– content during discharge indicates that the intercalation of NH 4 + in Ov-BSO is mainly in the form of −NH 3 . − Residual NH 4 + on the electrode surface resulted in a −NH + – signal. Interestingly, during the discharge state, the Bi 0 and Bi 2+ signals in the Bi 4f spectra (Figure h) and Se 2– in Se 3d spectra (Figure S18, Supporting Information) can be detected, which confirms the forming of BiSe and Bi, proving the conversion reaction, which is consistent with the XRD results.…”

Ostwald ripening mechanism-derived MnOOH induces lattice oxygen escape for efficient aqueous MnO2–Zn batteries

“…Especially the most common anion defect engineering-oxygen defect engineering. [62][63][64][65] First, the introduction of oxygen defects (O d ) can effectively improve the conductivity of MnO 2 materials. At the same time, undercoordinated Mn ions can serve as efficient transport channels for ion carriers, which improves the diffusion kinetics of ions and facilitates the transport of protons.…”