High-Performance Sodium-Ion Pseudocapacitors Based on Hierarchically Porous Nanowire Composites

Abstract

Electrical energy storage plays an increasingly important role in modern society. Current energy storage methods are highly dependent on lithium-ion energy storage devices, and the expanded use of these technologies is likely to affect existing lithium reserves. The abundance of sodium makes Na-ion-based devices very attractive as an alternative, sustainable energy storage system. However, electrodes based on transition-metal oxides often show slow kinetics and poor cycling stability, limiting their use as Na-ion-based energy storage devices. The present paper details a new direction for electrode architectures for Na-ion storage. Using a simple hydrothermal process, we synthesized interpenetrating porous networks consisting of layer-structured V(2)O(5) nanowires and carbon nanotubes (CNTs). This type of architecture provides facile sodium insertion/extraction and fast electron transfer, enabling the fabrication of high-performance Na-ion pseudocapacitors with an organic electrolyte. Hybrid asymmetric capacitors incorporating the V(2)O(5)/CNT nanowire composites as the anode operated at a maximum voltage of 2.8 V and delivered a maximum energy of ∼40 Wh kg(-1), which is comparable to Li-ion-based asymmetric capacitors. The availability of capacitive storage based on Na-ion systems is an attractive, cost-effective alternative to Li-ion systems.

Multidimensional Evolution of Carbon Structures Underpinned by Temperature‐Induced Intermediate of Chloride for Sodium‐Ion Batteries

“…In the inset of Figure 8D and in Figure 15S (Supporting Information), the largest ratio of SCP for 1D CNF‐700 samples is 87% at 0.9 mV s −1 , which matches well with the results of the slope. In addition, the ratios of SCP increase at mounting scan rates, further conforming that the electrochemical properties are determined by SCP 50. Thus, the strongest SCP was found for 1D CNF, which is corresponding to the best rate performances.…”

Aromatic porous-honeycomb electrodes for a sodium-organic energy storage device

“…3a,c, where R is the electrolyte resistance, CPE ¼ {T CPE (jo) a } -1 is a constant phase element with o being the angular frequency and a an empirical electrode roughness parameter, and where Z w is the Warburg impedance indicating a diffusion-limited electrochemical reaction. Each Nyquist plot above and below 2.8 V versus Na/Na þ shows a semicircle at high frequencies suggesting charge transfer at the polymeric framework/electrolyte (1 M NaClO 4 in propylene carbonate (PC)) interface and a characteristic linear diffusion-limited response at a tilt angle of close to 45°at low frequencies indicating incorporation of the ion in the electrode materials 17,29,47 . The FT-IR and RSMs (Fig.…”

“…There is an urgent need for alternative energy storage devices with a performance comparable to, or better than rechargeable lithium batteries. One possible approach is to use sodium as an alternative charge carrier [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] to lithium, as the cost of sodium carbonate (Na 2 CO 3 ), for example, is only 3% of Li 2 CO 3 (ref. 5).…”

Morphology and processing of aligned carbon nanotube carbon matrix nanocomposites

“…The tailorable energy harvesting 1-8 , storage [7][8][9][10][11] , and dissipation [12][13][14][15][16] capabilities of nanowires, nanofibers, and nanotubes make them prime candidates for next generation multifunctional material architectures. By integrating aligned nanofibers with a carbon matrix, materials with high strength, toughness, low density, and extended operating regimes may be synthesized.…”