Nonaqueous rechargeable lithium–oxygen batteries (LOBs) are one of the most promising candidates for future electric vehicles and wearable/flexible electronics. However, their development is severely ...hindered by the sluggish kinetics of the ORR and OER during the discharge and charge processes. Here, we employ MOF-assisted spatial confinement and ionic substitution strategies to synthesize Ru single atoms riveted with nitrogen-doped porous carbon (Ru SAs-NC) as the electrocatalytic material. By using the optimized Ru0.3 SAs-NC as electrocatalyst in the oxygen-breathing electrodes, the developed LOB can deliver the lowest overpotential of only 0.55 V at 0.02 mA cm–2. Moreover, in-situ DEMS results quantify that the e–/O2 ratio of LOBs in a full cycle is only 2.14, indicating a superior electrocatalytic performance in LOB applications. Theoretical calculations reveal that the Ru–N4 serves as the driving force center, and the amount of this configuration can significantly affect the internal affinity of intermediate species. The rate-limiting step of the ORR on the catalyst surface is the occurrence of 2e– reactions to generate Li2O2, while that of the OER pathway is the oxidation of Li2O2. This work broadens the field of vision for the design of single-site high-efficiency catalysts with maximum atomic utilization efficiency for LOBs.
NiOOH nanosheet/graphene hydrogels (H–NiOOH/GS), with mesoporous NiOOH nanosheets uniformly dispersed within the highly interconnected 3D graphene network, are constructed and studied for the first ...time by a mixed solvothermal and hydrothermal reaction. The effect of solvent composition on the morphology, phase, dispersibility of nanocrystal and hydrogel strength is systematically studied. As binder-free electrodes of supercapacitors, H–NiOOH/GS delivers high capacitance of 1162Fg−1 at 1Ag−1 with excellent rate capability (981Fg−1 at 20Ag−1). The charge-storage mechanisms of H–NiOOH/GS are in-depth investigated by quantifying the kinetics of charge storage, which reveals that NiOOH exhibits both capacitive effects and diffusion-controlled battery-type behavior during charge storage. Additionally, solvothermal-induced pure graphene hydrogels (H-GS) are also prepared and used as the negative electrode for the first time, which show an impressive specific capacitance of 425 and 368Fg−1 at 5 and 40mVs−1, respectively. Benefitting from the synergistic contribution of both positive and negative electrodes, the assembled H–NiOOH/GS//H-GS asymmetric supercapacitors achieve a remarkable energy density of 66.8Whkg−1 at a power density of 800Wkg−1, and excellent cycling stability with 85.3% capacitance retention after 8000 cycles, holding great promise for energy storage applications.
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•A new material, NiOOH nanosheet/GS hydrogel, was prepared for the first time.•The charge-storage mechanisms of the hydrogels were in-depth investigated.•NiOOH/GS hydrogels delivered high specific capacitances and good rate capability.•The assembled H-NiOOH/GS//H-GS achieved a remarkable energy density of 66.8 Wh kg-1.
All-solid-state sodium-ion battery is regarded as the next generation battery to replace the current commercial lithium-ion battery, with the advantages of abundant sodium resources, low price and ...high-level safety. As one critical component in sodium-ion battery, solid-state electrolyte should possess superior operational safety and design simplicity, yet reasonable high room-temperature ionic conductivity. This paper gives a comprehensive review on the recent progress in solid-state electrolyte materials for sodium-ion battery, including inorganic ceramic/glass-ceramic, organic polymer and ceramic-polymer composite electrolytes, and also provides a comparison of the ionic conductivity in various solid-state electrolyte materials. The development of solid-state electrolytes suggests a bright future direction: all solid-state sodium-ion battery could be fully used to power all electric road vehicles, portable electronic devices and large-scale grid support. Keywords: Sodium ion battery, Ionic conductivity, Inorganic solid electrolyte, Solid polymer electrolyte, Ceramic-polymer composite electrolyte
Water splitting is one of the ideal technologies to meet the ever increasing demands of energy. Many materials have aroused great attention in this field. The family of nickel-based sulfides is one ...of the examples that possesses interesting properties in water-splitting fields. In this paper, a controllable and simple strategy to synthesize nickel sulfides was proposed. First, we fabricated NiS2 hollow microspheres via a hydrothermal process. After a precise heat control in a specific atmosphere, NiS porous hollow microspheres were prepared. NiS2 was applied in hydrogen evolution reaction (HER) and shows a marvelous performance both in acid medium (an overpotential of 174 mV to achieve a current density of 10 mA/cm2 and the Tafel slope is only 63 mV/dec) and in alkaline medium (an overpotential of 148 mV to afford a current density of 10 mA/cm2 and the Tafel slope is 79 mV/dec). NiS was used in oxygen evolution reaction (OER) showing a low overpotential of 320 mV to deliver a current density of 10 mA/cm2, which is meritorious. These results enlighten us to make an efficient water-splitting system, including NiS2 as HER catalyst in a cathode and NiS as OER catalyst in an anode. The system shows high activity and good stabilization. Specifically, it displays a stable current density of 10 mA/cm2 with the applying voltage of 1.58 V, which is a considerable electrolyzer for water splitting.
3D macroscopic tin oxide/nitrogen-doped graphene frameworks (SnO2/GN) were constructed by a novel solvothermal-induced self-assembly process, using SnO2 colloid as precursor (crystal size of 3–7 nm). ...Solvothermal treatment played a key role as N,N-dimethylmethanamide (DMF) acted both as reducing reagent and nitrogen source, requiring no additional nitrogen-containing precursors or post-treatment. The SnO2/GN exhibited a 3D hierarchical porous architecture with a large surface area (336 m2g‑1), which not only effectively prevented the agglomeration of SnO2 but also facilitated fast ion and electron transport through 3D pathways. As a result, the optimized electrode with GN content of 44.23% exhibited superior rate capability (1126, 855, and 614 mAh g‑1 at 1000, 3000, and 6000 mA g‑1, respectively) and extraordinary prolonged cycling stability at high current densities (905 mAh g‑1 after 1000 cycles at 2000 mA g‑1). Electrochemical impedance spectroscopy (EIS) and morphological study demonstrated the enhanced electrochemical reactivity and good structural stability of the electrode.
A layered SnS2‐reduced graphene oxide (SnS2‐RGO) composite is prepared by a facile hydrothermal route and evaluated as an anode material for sodium‐ion batteries (NIBs). The measured electrochemical ...properties are a high charge specific capacity (630 mAh g−1 at 0.2 A g−1) coupled to a good rate performance (544 mAh g−1 at 2 A g−1) and long cycle‐life (500 mAh g−1 at 1 A g−1 for 400 cycles).
Progress in aqueous rechargeable batteries Liu, Jilei; Xu, Chaohe; Chen, Zhen ...
Green energy & environment,
January 2018, 2018-01-00, 2018-01-01, Letnik:
3, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Over the past decades, a series of aqueous rechargeable batteries (ARBs) were explored, investigated and demonstrated. Among them, aqueous rechargeable alkali-metal ion (Li+, Na+, K+) batteries, ...aqueous rechargeable-metal ion (Zn2+, Mg2+, Ca2+, Al3+) batteries and aqueous rechargeable hybrid batteries are standing out due to peculiar properties. In this review, we focus on the fundamental basics of these batteries, and discuss the scientific and/or technological achievements and challenges. By critically reviewing state-of-the-art technologies and the most promising results so far, we aim to analyze the benefits of ARBs and the critical issues to be addressed, and to promote better development of ARBs.
In this review, we focus on the fundamental basics of aqueous rechargeable batteries, and discuss recent scientific achievements in detail. Furthermore, challenges and research directions toward aqueous rechargeable batteries are also proposed. Display omitted
Abstract
A self-supporting Co
3
O
4
/graphene hybrid film has been constructed via vacuum filtration of Co(OH)
2
nanosheet and graphene, followed by a two-step thermal treatment. Within the hybrid ...film, Co
3
O
4
nanoparticles with size of 40~60 nm uniformly
in-situ
grew on the surface of graphene, forming a novel porous and interleaved structure with strong interactions between Co
3
O
4
nanoparticles and graphene. Such fascinating microstructures can greatly facilitate interfacial electron transportation and accommodate the volume changes upon Li ions insertion and extraction. Consequently, the binder-less hybrid film demonstrated extremely high reversible capacity (1287.7 mAh g
−
1
at 0.2 A g
−
1
), excellent cycling stability and rate capability (1110 and 800 mAh g
−
1
at 0.5 and 1.0 A g
−
1
, respectively).
The rational design of excellent electrocatalysts is significant for triggering the slow kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in rechargeable metal–air ...batteries. Hereby, we report a bifunctional catalytic material with core–shell structure constructed by Co3O4 nanowire arrays as cores and ultrathin NiFe-layered double hydroxides (NiFe LDHs) as shells (Co3O4@NiFe LDHs). The introduction of Co3O4 nanowires could provide abundant active sites for NiFe LDH nanosheets. Most importantly, the deposition of NiFe LDHs on the surface of Co3O4 can modulate the surface chemical valences of Co, Ni, and Fe species via changing the electron donor and/or electron absorption effects, finally achieving the balance and optimization of ORR and OER properties. By this core–shell design, the maximum ORR current densities of Co3O4@NiFe LDHs increase to 3–7 mA cm–2, almost an order of magnitude increases compared to pure NiFe LDH (0.45 mA cm–2). Significantly, an OER overpotential as low as 226 mV (35 mA cm–2) is achieved in the designed core–shell catalyst, which is comparable to and/or even better than those of commercial Ir/C. Hence, the primary zinc–air battery employing Co3O4@NiFe LDH as an air electrode achieves a high specific capacity (667.5 mA h g–1) and first-class energy density (797.6 W h kg–1); the rechargeable battery can show superior reversibility, excellent stability, and voltage gaps of ∼0.8 V (∼60% of round-trip efficiency) in >1200 continuous cycles. Furthermore, the flexible quasi-solid-state zinc–air battery with bendable ability holds practical potential in portable and wearable electronic devices.
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