Dynamic template directed construction of three-dimensional porous bismuth aerogels for high-rate Na-ion storage

Abstract

Aiming to achieve metallic bismuth (Bi) anode with constant accommodation of volume change, a dynamic template strategy is proposed for fabrication of highly adjustable Bi aerogel anode. In presence of...

Facile Galvanic Replacement Construction of Bi@C Nanosheets Array as Binder‐Free Anodes for Superior Sodium‐Ion Batteries

“…The presence of Na, P, and F elements can be attributed to the SEI film formed on the electrode surface during cycling. Therefore, the reversible alloying reaction mechanism of the Bi@C-NSA can be ascribed as the following: [48] Na + + e − + Bi ↔ NaBi (1)…”

Life Aging Effect as a Conditioning Process that Regulates the Performance of the Halogen-Free Mg Electrolyte

“…It can be noticed that R s , R SEI , R ct , and w s were reduced after aging, which confirms the role of aging in changing the Mg 2+ solvation barrier of HFE species. The diffusion coefficient of magnesium ( D Mg 2+ ) was calculated by the equation: D M g 2 + = true[ R 2 T 2 2 A 2 normaln 4 F 4 C 2 σ 2 true] , and the Warburg factor σ was calculated from the slope of the linear fitting ω –0.5 vs Z ′ at low frequencies of the relation Z ′ = R s + R ct + σω –0.5 , Figure c. The σ values were ∼510 and 466 for the cell with fresh and aging HFE, respectively, indicating that the aging electrolyte has relatively low Mg 2+ diffusion barrier resulting in enhanced electrochemical performance of the aging HFE.…”

“…Figure 6b shows the Nyquist plots of the Mg−S cell using fresh and aging HFE, the EIS spectrum shows a depressed two semicircles response at the middle-and high-frequency regions and a long line in the low-frequency region, representing the interphase contact resistance, the charge-transfer resistance, and ion-diffusion process resistance, respectively. 24 The discharge/charge curves exhibit two successive plateaus representing the conversion of higher-order polysulfides to lower-order polysulfides and vice versa, respectively. Figure 6e,g shows the cycling stability profiles of Mg−S coin cells with fresh and aging HFE at a current density of 0.02 mA cm −2 , respectively.…”

“…The cell with aging HFE shows relatively high anodic and cathodic current compared with the fresh HFE; furthermore, the voltage interval of the redox peaks decreased, indicative of the role of aging on reducing the solvation barrier so it does enhance the electrochemical performance of the HFE. Figure b shows the Nyquist plots of the Mg–S cell using fresh and aging HFE, the EIS spectrum shows a depressed two semicircles response at the middle- and high-frequency regions and a long line in the low-frequency region, representing the interphase contact resistance, the charge-transfer resistance, and ion-diffusion process resistance, respectively . EIS parameters were collected by simulating and fitting the experimental data using the Randles electrical circuit-based model and ZView software (inset Figure b) where R s , R SEI , R ct , and w s are the Ohmic resistance of the bulk cell, the resistance of the interfacial layer, the charge-transfer resistance, and Warburg impedance, respectively.…”

Probing the effect of ethylene carbonate on optimizing the halogen-free electrolyte performance for Mg sulfur batteries

“…EIS parameters were calculated via fitting the equivalent circuit (Randell circuit model) using ZView software and the obtained parameters are displayed in Table 2 . The diffusion coefficient of Mg 2+ (DMg 2+ ) was calculated by eqn: 23 , from linear fitting the of the relation Z ′ = R s + R ct + σω −0.5 ( ω −0.5 vs. Z ′), the Warburg factor σ was calculated from the slope at low frequencies, Fig. 5c .…”