skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


  • NSF Public Access
  • Search Results
  • Ab initio determination of a simultaneous dual-ion charging mechanism for Ni 0.25 Mn 0.75 O 2 through redox reactions of Ni 2+ /Ni 4+ and O 2- /O -
Title: Ab initio determination of a simultaneous dual-ion charging mechanism for Ni 0.25 Mn 0.75 O 2 through redox reactions of Ni 2+ /Ni 4+ and O 2- /O -
Over recent years, great efforts have been made to push the limits of layered transition metal oxides for secondary battery cathodes. This is particularly true for overall capacity, which has reached a terminal theoretical value for many materials. One avenue for increasing this capacity during charging is the intercalation of anions post cation deintercalation. This work investigates the charging mechanism of the P3-Na0.5Ni0.25 Mn0.75O2 cathode material through cation (Na) deintercalation and anion (ClO4) intercalation by means of density functional theory. The calculations corroborate experimental findings of increased capacity (135 mAh g-1 to 180 mAh g-1) through the intercalation of anions. However, this work demonstrates that a process of simultaneous cation deintercalation/anion intercalation is the primary charging mechanism, with charge compensation reactions of Ni2+/Ni4+ and O2-/O- occurring within the cathode material. To elucidate this simultaneous process, a novel method for computationally determining anion voltage in which one must consider full electrolyte interactions is proposed. Based on the results, it is believed that a simultaneous cation deintercalation/anion intercalation mechanism provides one potential avenue for the discovery of the next generation of secondary batteries.  more » « less
Award ID(s):
2028722
PAR ID:
10352918
Author(s) / Creator(s):
; ; ; ;
Date Published:
Journal Name:
Journal of Materials Chemistry A
ISSN:
2050-7488
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; (, Energy Material Advances)
    Manganese dioxide (MnO 2 ) with different crystal structures has been widely investigated as the cathode material for Zn-ion batteries, among which spinel λ -MnO 2 is yet rarely reported because Zn-ion intercalation in spinel lattice is speculated to be limited by the narrow three-dimensional tunnels. In this work, we demonstrate that Zn-ion insertion in spinel lattice can be enhanced by reducing particle size and elucidate an intriguing electrochemical reaction mechanism dependent on particle size. Specifically, λ -MnO 2 nanoparticles (NPs, ~80 nm) deliver a high capacity of 250 mAh/g at 20 mA/g due to large surface area and solid-solution type phase transition pathway. Meanwhile, severe water-induced Mn dissolution leads to the poor cycling stability of NPs. In contrast, micron-sized λ -MnO 2 particles (MPs, ~0.9  μ m) unexpectedly undergo an activation process with the capacity continuously increasing over the first 50 cycles, which can be attributed to the formation of amorphous MnO x nanosheets in the open interstitial space of the MP electrode. By adding MnSO 4 to the electrolyte, Mn dissolution can be suppressed, leading to significant improvement in the cycling performance of NPs, with a capacity of 115 mAh/g retained at 1 A/g for over 500 cycles. This work pinpoints the distinctive impacts of the particle size on the reaction mechanism and cathode performance in aqueous Zn-ion batteries. 
    more » « less
  2. ; ; ; ; ; ; ; ; ; ; et al (, Advanced Functional Materials)
    Abstract New acceptor‐type graphite intercalation compounds (GICs) offer candidates of cathode materials for dual‐ion batteries (DIBs), where superhalides represent the emerging anion charge carriers for such batteries. Here, the reversible insertion of [LiCl2]−into graphite from an aqueous deep eutectic solvent electrolyte of 20mLiCl+20mcholine chloride is reported. [LiCl2]−is the primary anion species in this electrolyte as revealed by the femtosecond stimulated Raman spectroscopy results, particularly through the rarely observed H–O–H bending mode. The insertion of Li–Cl anionic species is suggested by7Li magic angle spinning nuclear magnetic resonance results that describe a unique chemical environment of Li+ions with electron donors around.2H nuclear magnetic resonance results suggest that water molecules are co‐inserted into graphite. Density functional theory calculations reveal that the anionic insertion of hydrated [LiCl2]−takes place at a lower potential, being more favorable. X‐ray diffraction and the Raman results show that the insertion of [LiCl2]−creates turbostratic structure in graphite instead of forming long‐range ordered GICs. The storage of [LiCl2]−in graphite as a cathode for DIBs offers a capacity of 114 mAh g−1that is stable over 440 cycles. 
    more » « less
  3. ; ; ; ; ; ; ; ; (, Advanced Functional Materials)
    Abstract Si‐based anodes with a stiff diamond structure usually suffer from sluggish lithiation/delithiation reaction due to low Li‐ion and electronic conductivity. Here, a novel ternary compound ZnSi2P3with a cation‐disordered sphalerite structure, prepared by a facile mechanochemical method, is reported, demonstrating faster Li‐ion and electron transport and greater tolerance to volume change during cycling than the existing Si‐based anodes. A composite electrode consisting of ZnSi2P3and carbon achieves a high initial Coulombic efficiency (92%) and excellent rate capability (950 mAh g−1at 10 A g−1) while maintaining superior cycling stability (1955 mAh g−1after 500 cycles at 300 mA g−1), surpassing the performance of most Si‐ and P‐based anodes ever reported. The remarkable electrochemical performance is attributed to the sphalerite structure that allows fast ion and electron transport and the reversible Li‐storage mechanism involving intercalation and conversion reactions. Moreover, the cation‐disordered sphalerite structure is flexible to ionic substitutions, allowing extension to a family of Zn(Cu)Si2+xP3solid solution anodes (x= 0, 2, 5, 10) with large capacity, high initial Coulombic efficiency, and tunable working potentials, representing attractive anode candidates for next‐generation, high‐performance, and low‐cost Li‐ion batteries. 
    more » « less
  4. ; ; ; ; ; ; ; ; (, Angewandte Chemie International Edition)
    Abstract Dual‐ion batteries that use anions and cations as charge carriers represent a promising energy‐storage technology. However, an uncharted area is to explore transition metals as electrodes to host carbonate in conversion reactions. Here we report the reversible conversion reaction from copper to Cu2CO3(OH)2, where the copper electrode comprising K2CO3and KOH solid is self‐sufficient with anion‐charge carriers. This electrode dissociates and associates K+ions during battery charge and discharge. The copper active mass and the anion‐bearing cathode exhibit a reversible capacity of 664 mAh g−1and 299 mAh g−1, respectively, and relatively stable cycling in a saturated mixture electrolyte of K2CO3and KOH. The results open an avenue to use carbonate as a charge carrier for batteries to serve for the consumption and storage of CO2. 
    more » « less
  5. ; ; ; ; ; ; (, Journal of Materials Chemistry A)
    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. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email