Faster Diffusion and Higher Lithium-Ion Intercalation Capacity in Pb-Jarosite than Na-Jarosite

Abstract

Pb-jarosite, Pb0.5Fe3(SO4)2(OH)6, was investigated for the first time as an intercalation cathode for lithium-ion batteries. Despite having a lower theoretical specific capacity than its Na-jarosite analogue, NaFe3(SO4)2(OH)6, bulk Pb-jarosite displayed higher lithium-ion capacity, especially at higher current rates. The greater lithium storage is attributed to more kinetically facile diffusion of lithium in Pb-jarosite, as evidenced by potentiostatic intermittent titration technique data, indicating an average diffusion coefficient over 10 times larger. Inductively coupled plasma–optical emission spectroscopy and X-ray diffraction (XRD) measurements showed that the substitution of divalent Pb2+ into monovalent Na+ sites led to an increased number of cation vacancies and a more open structure to facilitate lithium diffusion. Ex situ XRD measurements showed that Pb-jarosite is more resilient to the semireversible crystalline-to-amorphous phase transformation that occurs in Na-jarosite over many cycles. These findings demonstrate that multivalent cation substitution in jarosite materials can significantly improve their performance as intercalation cathodes.

Insight on the Energy Storage Mechanism and Kinetic Dynamic of Manganese Oxide‐Based Aqueous Zinc‐Ion Batteries

“…where R, T, n, F, and c are the gas constant, the absolute temperature, the number of electrons involved in the reaction, the Faraday constant, and the Zn 2+ concentration, respectively. From Equation ( 5), the 𝜎 is inversely proportional to D −1/2 , [123,124] which means that the smaller the 𝜎 obtained, the larger the D. As shown in Figure 10d, Fu et al analyzed the 𝜎 of the Mn-based material with the porous framework and N-doping (MnO x @N-C) cathode in the AZIB. [114] Thanks to the improved conductive network obtained by compounding with the MOF, MnO x @N-C has a much smaller 𝜎 value, which also proves that the kinetics are greatly improved.…”

“…In addition to the graphical method, the σ can also be calculated by the following equation [ 119–122 ] $$$$\begin{equation} {\sigma =\frac{\textit{RT}}{\sqrt{2}{n}^{2}A{F}^{2}c\sqrt{D}}} \end{equation}$$$$where R , T , n , F , and c are the gas constant, the absolute temperature, the number of electrons involved in the reaction, the Faraday constant, and the Zn 2+ concentration, respectively. From Equation (5), the σ is inversely proportional to D −1/2 , [ 123,124 ] which means that the smaller the σ obtained, the larger the D . As shown in Figure 10d, Fu et al.…”

An overview of hydroxy-based polyanionic cathode insertion materials for metal-ion batteries

“…Moving away from monovalent alkali ion-based jarosite, recently an isostructural divalent Pb-based jarosite having formula Pb 0.5 Fe 3 (SO 4 ) 2 (OH) 6 was reported as cathode material for Li-ion batteries. 112 There are two main advantages of Pb substitution in jarosite system. The aliovalent substitution of divalent Pb 2+ for monovalent Na + in parent jarosite structure can create vacancies and expedite facile alkali-ion migration during (de)insertion reaction.…”

“…Naturally occuring hydroxyphosphate-based minerals with potential application in design of battery insertion materials [112][113][114][115][116]. …”