Enhancing lithium-ion and electric conductive Li2FeSiO4 cathode through in situ boron-doping and carbon-coating strategy

High-Rate-Capacity Cathode Based on Zn-Doped and Carbonized Polyacrylonitrile-Coated Na4MnV(PO4)3 for Sodium-Ion Batteries

“…The slope of the Z′−ω –1/2 curves is the Warburg coefficient. Equation can be used to calculate the specific values of the Na + diffusion coefficient ( D Na + ). , D = R 2 T 2 2 A 2 n 4 F 4 C 2 σ 2 where R , T , A , n , F , C , and σ are the gas constant, absolute temperature, electrode surface area, the number of transferred electrons, the Faraday constant, the Na + concentration, and the Warburg coefficient (obtained from eq ), respectively . All calculated data from the Nyquist curves are given in Table S5.…”

“…69 where R, T, A, n, F, C, and σ are the gas constant, absolute temperature, electrode surface area, the number of transferred electrons, the Faraday constant, the Na + concentration, and the Warburg coefficient (obtained from eq 4), respectively. 71 All calculated data from the Nyquist curves are given in Table S5. It is obvious that the NMZVP@cPAN cathode exhibits the smallest charger transfer resistance and higher Na + diffusion coefficient (1.1097 × 10 −10 cm 2 •s −1 ), confirming that Zn doping can improve the kinetic performance and reduce the electrochemical polarization of the cathode materials.…”

Nanosheet-Assembled Hierarchical Petal-like Na4MnV(PO4)3@Carbonized-Polyaniline Microspheres for Stable Sodium-Ion Batteries

“…Thus, ex situ XRD was performed during the initial charge/discharge process, and the pattern is depicted in Figure 4e. The peaks situated at 19.4°, 19.8°, 22.9°, 31.5°, and 34.2°are indexed to (2-10), ( 104), (2-13), (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16), and (300) facets, respectively. Evidently, the phenomenon of a right shift occurs for all the peaks, especially (104), (2-13), (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16), and (300) peaks (right side of Figure 4e) during the charging process up to 3.6 V, corresponding to solid-solution reaction for V 4+ /V 3+ redox (Na 4 MnV(PO 4 ) 3 → Na 3 MnV(PO 4 ) 3 ).…”

“…The peaks situated at 19.4°, 19.8°, 22.9°, 31.5°, and 34.2°are indexed to (2-10), ( 104), (2-13), (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16), and (300) facets, respectively. Evidently, the phenomenon of a right shift occurs for all the peaks, especially (104), (2-13), (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16), and (300) peaks (right side of Figure 4e) during the charging process up to 3.6 V, corresponding to solid-solution reaction for V 4+ /V 3+ redox (Na 4 MnV(PO 4 ) 3 → Na 3 MnV(PO 4 ) 3 ). 28,29,53 When the voltage is near 3.8 V, the (2-10) and (104) peaks almost combine into one, which can be ascribed to a biphasic transition for Mn 3+ /Mn 2+ (Na 3 MnV-(PO 4 ) 3 → Na 2 MnV(PO 4 ) 3 ).…”

“…For the world’s better transition to a green economy, it is particularly key to develop advanced energy storage and conversion systems. , Exploiting a rechargeable battery with long cycling life and high energy density is critical to the advances of novel energy storage systems (ESSs). , Despite the widespread use of lithium-ion batteries (LIBs) in various fields of electronic devices, their limited availability and cost prevented them from being applied in large-scale ESSs. − Naturally, high-performance sodium-ion batteries (SIBs) are suitable for development in alternative ESSs due to the lower cost, abundant resources, and similar physicochemical mechanism to LIBs. − Therefore, it is urgent to advance cathode electrodes with high-rate performance and stable lifespan, which largely dominate the SIB performance advancement. , …”