Rational construction of 3D porous Fe3N@C frameworks for high-performance sodium-ion half/full batteries

Facilely Fabricating F-Doped Fe3N Nanoellipsoids Grown on 3D N-Doped Porous Carbon Framework as a Preeminent Negative Material

“…The SEI film resistances (R f ) for the F-Fe 3 N/NPCF, Fe 3 N/NPCF and Fe x N/Fe/NPCF negative electrodes are 34, 50 and 65 Ω, and the charge transfer resistances (R ct ) are 65, 74 and 86 Ω. The lower R f and R ct values of the F-Fe 3 N/NPCF negative electrode would contribute to the speedy lithium ion and electron movement [ 45 , 46 ]. Furthermore, we counted three diffusion coefficients of lithium ion (D Li + ) for the F-Fe 3 N/NPCF, Fe 3 N/NPCF and Fe x N/Fe/NPCF negative electrodes abiding by Equation (1) [ 47 ]: D Li + = (R 2 T 2 )/(2A 2 n 4 F 4 C 2 σ 2 ) …”

Ultrafast and ultrastable FeSe2 embedded in nitrogen-doped carbon nanofibers anode for sodium-ion half/full batteries

“…where M B and m B are the relative molecular weight and weigh, ∆E S is the change of regulated voltage, and ∆E t is the voltage variation of the discharge pulse, A and V m are the electrode area and the molar volume, and L is the thickness of the electrode material on the collector (figure 6(d)) [13,36,46]. As depicted in figure 6(e), the diffusion coefficient of Na + in the FeSe 2 @NCF electrode was calculated in the range of 2.96 × 10 -11 to 5.38 × 10 −8 cm 2 s −1 , superior to those of reported FeSe 2 -based materials, which can account for the high-rate performance of the FeSe 2 @NCF electrode [24,28,30,34,38,47].…”

“…The material and electrochemical characterization of Na 3 V 2 (PO 4 ) 3 /C composites are shown in figure S10, which can provide a reversible capacity of 78 mAh g −1 at a current density of 0.2 A g −1 . The weight ratio of the cathode to anode determined by the stable capacity could be controlled at 4.0 and the Na 3 V 2 (PO 4 ) 3 /C cathode is limited to prevent Na plating on the FeSe 2 @NCF anode side by regulating the negative/positive capacity ratio of ≈ 1.3 [14,[46][47][48]. Thus, the active mass loadings of FeSe 2 @NCF and Na 3 V 2 (PO 4 ) 3 /C electrodes are about 0.737 and 2.948 mg cm −2 , respectively.…”

Ti3C2Tx MXene-embedded MnO2-based hydrophilic electrospun carbon nanofibers as a freestanding electrode for supercapacitors

“…4 Pseudocapacitive materials store energy by surface redox reactions at an electrode-electrolyte interface or by intercalation reactions and can provide a higher energy density and power density than electric double-layer materials. 5,6 Among the different types of pseudocapacitive materials, manganese dioxide (MnO 2 ) 7 has superior theoretical specific capacitance (1380 F g À1 ), low cost, good safety, non-toxic nature, and environmental friendliness. However, MnO 2 has low electrical conductivity, which significantly limits the electrochemical performance, especially in high power scenarios.…”

“…4 Pseudocapacitive materials store energy by surface redox reactions at an electrode–electrolyte interface or by intercalation reactions and can provide a higher energy density and power density than electric double-layer materials. 5,6…”