Binder-Free Electrospun Ni–Mn–O Nanofibers Embedded in Carbon Shells with Ultrahigh Energy and Power Densities for Highly Stable Next-Generation Energy Storage Devices

Abstract

We demonstrate the fabrication of binder-free electrospun nickel− manganese oxides embedded into carbon-shell fibrous electrodes. The morphological and structural properties of the assembled electrode materials were elucidated by high-resolution transmission electron microscopy (HR-TEM), field-emission scanning electron microscopy, and glancing-angle X-ray diffraction. The fibrous structure of the electrodes was retained even after annealing at high temperatures. The X-ray photoelectron spectroscopy and HR-TEM analyses revealed the formation of nickel and manganese oxides in multiple oxidation states (Ni 2+ , Ni 3+ , Mn 2+ , Mn 3+ , and Mn 4+ ) embedded in the carbon shell. The embedded nickel−manganese oxides into the carbon matrix fibrous electrodes exhibit an excellent capacitance (1082 F/g) in 1 M K 2 SO 4 at 1 A/g and possess a high rate capability of 73% at 5 A/g. The high rate capability and capacitance can be attributed to the presence of carbon crosslinked channels, the binder-free nature of the electrodes, and various oxidation states of the Ni−Mn oxides. The asymmetric supercapacitor device constructed of the asfabricated nanofibers and the bio-derived microporous carbon as the positive and negative electrodes, respectively, sustains up to 1.9 V with a high specific capacitance at 1.5 A/g of 108 F/g. The nanofibrous//bio-derived device exhibits an outstanding specific energy of 54.2 W h/kg with a high specific power of 1425 W/kg. Interestingly, the tested device maintains a high capacitive retention of 92% upon cycling over 10,000 charging/discharging cycles.

Ribbon-like Nickel Cobaltite with Layer-by-Layer-Assembled Ordered Nanocrystallites for Next-Generation All-Solid-State Hybrid Supercapatteries

“…2,3 However, the low energy delivery efficiency of supercapacitors resulting from restricted ion diffusion in the electrode materials is a major concern for their comprehensive applicability. 4 However, in batteries, facilitated Faradaic reactions on the near-inclusive material surface lead to supplemented energy delivery efficiency of the device. 5 Apart from these advantages, a battery suffers from the limitation of subpar power density due to polarization (ohmic and kinetic)-induced cell voltage fading, ascribing to low reversibility in the redox kinetics.…”

Binder-free Mn–V–Sn oxyhydroxide decorated with metallic Sn as an earth-abundant supercapattery electrode for intensified energy storage

“…Asymmetric supercapacitors are extremely promising in realworld applications owing to their wide operating voltage window upon the proper combination of negative and positive electrodes. 7,41,46,95 Therefore, a sandwich-like supercapacitor cell was assembled using the SMVS ternary metal oxyhydroxide composite and hierarchical nitrogen-doped carbon (HDC) as the anode and cathode, respectively, separated by a cellulose lter paper. It is worth mentioning that HDC is a good cathode material, producing high capacitance with a wide operating window of 1.2 V; see the ESI † for more details.…”

“…[3][4][5][6] In recent years, research on developing new sustainable energy storage devices has received considerable attention, particularly those related to supercapacitors. [7][8][9] Supercapacitors enjoy unique properties, over conventional capacitors and batteries, including their low fabrication cost, ease of fabrication, generation of less thermochemical heat, and simpler charge storage mechanisms, along with high power density and coulombic efficiency. [10][11][12][13][14] However, their limited energy densities pose the biggest obstacle to their widespread use in the energy storage sector.…”

Toward the Proper Selection of Carbon Electrode Materials for Energy Storage Applications: Experimental and Theoretical Insights

“…On the other hand, the pseudo and battery-like types are the characteristics of Faradaic materials that allow ion intercalation or redox reactions. , Although Faradaic materials enjoy a higher specific energy than the EDL counterparts, they usually suffer from lower power density and cycling instability due to the decomposition and/or corrosion of the electrode materials in high potential windows. In this regard, hybrid electrodes that contain both carbon materials and faradic materials have been proposed. − Tian et al studied MoS 2 /MoO 2 nanoparticles grown on the surface of CNTs, which showed a capacitance of 228.4 F/g at 0.5 A/g, a specific energy of 11.88 Wh/kg, and a specific power of 2 kW/kg with high cycling stability in KOH electrolyte at 0.55 V . Samuel et al used a Zn 2 SnO 4 /SnO 2 /CNTs nanocomposite as a supercapacitor electrode that exhibited a capacitance of 260 F/g at 10 A/g in 6 M KOH and a potential window of 1 V .…”