High‐Throughput Production of Cheap Mineral‐Based Heterostructures for High Power Sodium Ion Capacitors

Abstract

The high‐throughput scalable production of inexpensive and efficient electrode materials at high current densities demanded by industry is a huge challenge for large‐scale implementation of energy storage technologies. Here, inspired by theoretical calculations that a FeS2/TiO2 heterostructure with built‐in electric field (BEF) can reduce the reaction energy barrier and enhance charge transport, the scalable production of cheap FeS2/TiO2 heterostructure is fabricated by utilizing natural ilmenite as precursor, exhibiting excellent electrochemical performances for sodium‐ion capacitors (SICs) anode. Assembling it with activated carbon (AC) cathode for SICs delivers high energy density (73.7 Wh kg−1) and high power density (10 kW kg−1) as well as outstanding cycle lifespan. Impressively, the method breaks through the traditional preparation approach by using natural minerals instead of high‐purity chemical raw materials as precursors for constructing heterojunctions, and price of the mineral is nearly five orders of magnitude lower than that of commercial chemical raw materials with high‐purity, which greatly reduces raw materials cost and is available for mass production. Similarly, the method can be extended to utilize other minerals to construct heterostructures, thus achieving expanded electrochemical performance, which exhibits huge potentials in electrochemical energy storage.

In Situ Reconstructed Zn doped FexNi(1−x)OOH Catalyst for Efficient and Ultrastable Oxygen Evolution Reaction at High Current Densities

“…It is noted that the binding energy of Fe 3+ peaks exhibits a positive shift of 0.5 eV for Zn‐(Ni/FeOOH)@NF compared to Ni/FeOOH@NF. [ 36 ] This result suggests that Fe species in Zn‐(Ni/FeOOH)@NF are in a higher oxidation state, favorable for rapid water oxidation. [ 13 ] Moreover, the modification of Zn element to Ni/FeOOH@NF leads to an evident negative shift (0.5 eV) of Ni 0 , while has almost no effect on Ni 2+ .…”

Low-Cost, High-Energy Na-Ion Hybrid Supercapacitors

“…The Na-ion diffusion coefficient was calculated based on the GITT curves (Figure c). The values display in the range of 10 –9 –10 –11 cm 2 s –1 , which are 2 orders of magnitude higher than the LiFePO 4 or other traditional cathodes. − The GITT curve is shown in Figure S7. The detailed calculation processes are provided in the Supporting Information Experiment Section.…”

“…Zhou’ s group successfully prepared a composite of LiFePO 4 particles trapped in fast bifunctional conductor rGO&C@Li 3 V 2 (PO 4 ) 3 nanosheets, and it is applied to the lithium-ion hybrid capacitor, showing high-power density and energy density . Zou’ s group prepared a cheap FeS 2 /TiO 2 heterostructure and used it as a battery anode and active carbon (AC) as a capacitive cathode, which also showed excellent electrochemical performance . However, there is still a lack of suitable electrode materials with high performance for the Na-ion hybrid supercapacitor. − …”

“…51 Zou' s group prepared a cheap FeS 2 /TiO 2 heterostructure and used it as a battery anode and active carbon (AC) as a capacitive cathode, which also showed excellent electrochemical performance. 52 However, there is still a lack of suitable electrode materials with high performance for the Na-ion hybrid supercapacitor. 57−62 In this work, we have successfully synthesized a mesoporous Na 3 Fe 2 (PO 4 )P 2 O 7 (denoted by M-NFPP@C) by the sol−gel method by adding polyvinyl alcohol (PVA) as pore agents and carbon sources.…”

Metal–Organic Framework Materials for Electrochemical Supercapacitors

“…Environmental pollution caused by the consumption of coal, oil, natural gas, and other non-renewable resources is very serious; thus, developing new green energy storage devices is increasingly fundamental. Supercapacitors, as electrochemical energy storage unit, have broad application prospects in portable devices, hybrid electric vehicles, military industries, national defenses, and other fields due to their superiority of high charging and discharging efficiency, long circular life, and environmental friendliness [1][2][3][4][5]. Supercapacitors can be divided into electric double-layer capacitors (EDLCs) (Fig.…”