Aqueous zinc ion batteries (ZIBs) are emerging as a highly promising alternative technology for grid-scale applications where high safety, environmental-friendliness, and high specific capacities are needed. It remains a significant challenge, however, to develop a cathode with a high rate capability and long-term cycling stability. Here, we demonstrate diffusion-controlled behavior in the intercalation of zinc ions into highly porous, Mn 4+ -rich, and low-band-gap Ni x Mn 3−x O 4 nano-particles with a carbon matrix formed in situ (with the composite denoted as Ni x Mn 3−x O 4 @C, x = 1), which exhibits superior rate capability (139.7 and 98.5 mA h g −1 at 50 and 1200 mA g −1 , respectively) and outstanding cycling stability (128.8 mA h g −1 remaining at 400 mA g −1 after 850 cycles). Based on the obtained experimental results and density functional theory (DFT) calculations, cation-site Ni substitution combined with a sufficient doping concentration can decrease the band gap and effectively improve the electronic conductivity in the crystal. Furthermore, the amorphous carbon shell and highly porous Mn 4+ -rich structure lead to fast electron transport and short Zn 2+ diffusion paths in a mild aqueous electrolyte. This study provides an example of a technique to optimize cathode materials for high-performance rechargeable ZIBs and design advanced intercalation-type materials for other energy storage devices.
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A carboxylate- and pyridine-based organic anode material for K-ion batteries
Developing high-capacity, stable, and sustainable K-ion batteries (KIBs) is an ongoing challenge due to the lack of high-performance and environmentally benign electrode materials. To address this challenge, organic electrode materials that are affordable, abundant, highly sustainable, highly tunable and flexible offer opportunities. Herein, we report a novel N-containing carboxylate salt, K 2 C 12 H 6 N 2 O 4 (K-DCA), with two bipyridine moieties and two carboxylate groups. The carboxylate- and pyridine-based active centers in K-DCA can reversibly react with four K-ions to provide a specific capacity of 163.3 mA h g −1 with a pair of redox plateaus centered at ∼0.8 V. When coupling with nitrogen-doped reduced graphene oxide (NrGO), the composite anode material, K-DCA-NrGO, demonstrates a high specific capacity of 225.25 mA h g −1 and increased capacity retention during long-term cycling. Additionally, the reaction kinetics and mechanism studies demonstrate that the composite exhibits low overpotentials, low interphase resistance, a partial pseudo-capacitance behavior, and stable chemical/morphological structures upon cycling, which contribute to the fast kinetics and long cycle life.
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- Award ID(s):
- 2154145
- PAR ID:
- 10403714
- Date Published:
- Journal Name:
- New Journal of Chemistry
- Volume:
- 46
- Issue:
- 39
- ISSN:
- 1144-0546
- Page Range / eLocation ID:
- 18890 to 18898
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Li2S is one of the most promising cathode materials for Li‐ion batteries because of its high theoretical capacity and compatibility with Li‐metal‐free anode materials. However, the poor conductivity and electrochemical reactivity lead to low initial capacity and severe capacity decay. In this communication, a nitrogen and phosphorus codoped carbon (N,P–C) framework derived from phytic acid doped polyaniline hydrogel is designed to support Li2S nanoparticles as a binder‐free cathode for Li–S battery. The porous 3D architecture of N and P codoped carbon provides continuous electron pathways and hierarchically porous channels for Li ion transport. Phosphorus doping can also suppress the shuttle effect through strong interaction between sulfur and the carbon framework, resulting in high Coulombic efficiency. Meanwhile, P doping in the carbon framework plays an important role in improving the reaction kinetics, as it may help catalyze the redox reactions of sulfur species to reduce electrochemical polarization, and enhance the ionic conductivity of Li2S. As a result, the Li2S/N,P–C composite electrode delivers a stable capacity of 700 mA h g−1with average Coulombic efficiency of 99.4% over 100 cycles at 0.1C and an areal capacity as high as 2 mA h cm−2at 0.5C.
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Current commercial batteries are mainly metal based, with metal elements in charge carriers and/or electrode materials, which poses potential economic and environmental concerns due to the heavy use of nonrenewable metals. Thus, metal-free batteries present a unique opportunity as sustainable energy storage devices, though the relevant research is still in its infancy. Herein, we present an all-organic metal-free NH 4 + ion full battery that can operate at a low temperature of 0 °C, by using polypyrrole (PPy) as the cathode, polyaniline (PANI) as the anode, and 19 m ammonium acetate aqueous solution as electrolyte. For the first time, PPy is demonstrated as a high-capacity host material for both NH 4 + and K + storage, when cycled in water in salt electrolytes (WiSEs). When tested in a three-electrode cell containing 25 m NH 4 CH 3 COO electrolyte, PPy exhibits an impressive capacity of 125 mA h g −1 at a specific current of 1 A g −1 and retains 43.61 mA h g −1 at 25 A g −1 . Additionally, a full battery is assembled using the PPy cathode and PANI anode coupled with 19 m NH 4 CH 3 COO WiSE. This battery is found to deliver a capacity of 78.405 mA h g −1 at 25 °C and 49.083 mA h g −1 at 0 °C with a capacity retention of 71.83% after 200 cycles, demonstrating its potential for operations at low temperatures. Additionally, the physiochemical properties of NH 4 + -based WiSEs are examined by Raman and nuclear magnetic resonance (NMR) spectroscopies, to explore their electrochemical behaviors and the fundamental effect of salt concentration on the electrolyte characteristics. This study presents the first non-metal battery with potential for low-temperature applications and opens the door to future metal-free electronics that would generate long-term benefits to the environment.more » « less
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Metallic sulfide anodes show great promise for sodium‐ion batteries due to their high theoretic capacities. However, their practical application is greatly hampered by poor electrochemical performance because of the large volume expansion of the sulfides and the sluggish kinetics of the Na+ions. Herein, a porous bimetallic sulfide of the SnS/Sb2S3heterostructure is constructed that is encapsulated in the sulfur and nitrogen codoped carbon matrix (SnS/Sb2S3@SNC) by a facile and scalable method. The porous structure can provide void space to alleviate the volume expansion upon cycling, guaranteeing excellent structural stability. The unique heterostructure and the S, N codoped carbon matrix together facilitate fast‐charge transport to improve reaction kinetics. Benefitting from these merits, the SnS/Sb2S3@SNC electrode exhibits high capacities of 425 mA h g−1at 200 mA g−1after 100 cycles, and 302 mA h g−1at 500 mA g−1after 400 cycles. Moreover, the SnS/Sb2S3@SNC anode shows an outstanding rate performance with a capacity of over 200 mA h g−1at a high current density of 5000 mA g−1. This study provides a new strategy and insight into the design of electrode materials with the potential for the practical realization and applications of next‐generation batteries.
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Cobalt telluride anchored to nitrogen-rich carbon dodecahedra (CoTe@NCD) was synthesized by simultaneous pyrolysis-tellurium melt impregnation of ZIF-67 MOFs. The purely thermal method involved no secondary chemicals and no waste byproducts. The result is a microstructure consisting of nanoscale 86 wt% CoTe intermetallic nanoparticles contained within a thin N-rich carbon matrix. During electrochemical cycling, the 21 nm average diameter CoTe provides short diffusion paths for Na + /K + ions, which in conjunction with the electrically conducting carbon matrix allow for rapid potassiation or sodiation. As potassium ion battery (PIB and KIB) and sodium ion battery (NIB and SIB) anodes, CoTe@NCD demonstrates attractive reversible capacity, promising cycling stability, and state-of-the-art rate performance. For example, as a KIB anode, the CoTe@NCD electrode exhibits a reversible capacity of 380 mA h g −1 at 50 mA g −1 and a fast charge capacity of 136 mA h g −1 at 1000 mA g −1 . As a NIB anode, it also displays excellent rate capability achieving 620 mA h g −1 at 50 mA g −1 and 345 mA h g −1 at 1000 mA g −1 .more » « less
- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/d2nj03447f
