An official website of the United States government
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
Reversible Insertion of Mg‐Cl Superhalides in Graphite as a Cathode for Aqueous Dual‐Ion Batteries
Abstract Oxidative anion insertion into graphite in an aqueous environment represents a significant challenge in the construction of aqueous dual‐ion batteries. In dilute aqueous electrolytes, the oxygen evolution reaction (OER) dominates the anodic current before anions can be inserted into the graphite gallery. Herein, we report that the reversible insertion of Mg‐Cl superhalides in graphite delivers a record‐high reversible capacity of 150 mAh g−1from an aqueous deep eutectic solvent comprising magnesium chloride and choline chloride. The insertion of Mg‐Cl superhalides in graphite does not form staged graphite intercalation compounds; instead, the insertion of Mg‐Cl superhalides makes the graphite partially turbostratic.
more »
« less
- Award ID(s):
- 1920368
- PAR ID:
- 10236238
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 59
- Issue:
- 45
- ISSN:
- 1433-7851
- Page Range / eLocation ID:
- p. 19924-19928
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Abstract Intermediates relevant to cobalt‐catalyzed alkene hydroformylation have been isolated and evaluated in fundamental organometallic transformations relevant to aldehyde formation. The 18‐electron (R,R)‐(iPrDuPhos)Co(CO)2H has been structurally characterized, and it promotes exclusive hydrogenation of styrene in the presence of 50 bar of H2/CO gas (1:1) at 100 °C. Deuterium‐labeling studies established reversible 2,1‐insertion of styrene into the Co−D bond of (R,R)‐(iPrDuPhos)Co(CO)2D. Whereas rapid β‐hydrogen elimination from cobalt alkyls occurred under an N2atmosphere, alkylation of (R,R)‐(iPrDuPhos)Co(CO)2Cl in the presence of CO enabled the interception of (R,R)‐(iPrDuPhos)Co(CO)2C(O)CH2CH2Ph, which upon hydrogenolysis under 4 atm H2produced the corresponding aldehyde and cobalt hydride, demonstrating the feasibility of elementary steps in hydroformylation. Both the hydride and chloride derivatives, (X=H−, Cl−), underwent exchange with free13CO. Under reduced pressure, (R,R)‐(iPrDuPhos)Co(CO)2Cl underwent CO dissociation to form (R,R)‐(iPrDuPhos)Co(CO)Cl.more » « less
-
Abstract Rechargeable Mg batteries are a promising energy storage technology to overcome the limitations inherent to Li ion batteries. A critical challenge in advancing Mg batteries is the lack of suitable cathode materials. In this work, we report a cathode design that incorporates S functionality into two‐dimensional metal‐organic‐frameworks (2D‐MOFs). This new cathode material enables good Mg2+storage capacity and outstanding cyclability. It was found that upon the initial Mg2+insertion and disinsertion, there is an apparent structural transformation that crumbles the layered 2D framework, leading to amorphization. The resulting material serves as the active material to host Mg2+through reduction and/or oxidation of S and, to a limited extent, O. The reversible nature of S and O redox chemistry was confirmed by spectroscopic characterizations and validated by density functional calculations. Importantly, during the Mg2+insertion and disinsertion process, the 2D nature of the framework was maintained, which plays a key role in enabling the high reversibility of the MOF cathode.more » « less
-
Abstract A full cell chemistry of aqueous dual‐ion battery (DIB) was reported, comprising the graphite cathode and 3,4,9,10‐perylenetetracarboxylic diimide (PTCDI) as the anode. This DIB employed a mixture aqueous electrolyte: 5 mtributylmethylammonium (TBMA) chloride plus 5 mMgCl2, where [MgCl3]−and TBMA+serve as the charge carriers for cathode and anode of the DIB, respectively. This novel full cell exhibited a specific capacity of around 41 mAh g−1based on the total active mass of both electrodes with an average operation voltage of 1.45 V and stable cycling for 400 cycles.more » « less
-
Abstract With remarkably few exceptions, aquatic vertebrates maintain internal Cl−homeostasis despite strong and sometimes fluctuating Cl−concentration gradients between extracellular fluids and external environments. In this “Perspective,” we discuss recent advances in the understanding of epithelial Cl−transport at the molecular level within key osmoregulatory organs in fishes. New insights into mechanisms for epithelial Cl−transport in basal lineages are highlighted to provide an evolutionary context. We describe Cl−transport processes that employ: cystic fibrosis transmembrane conductance regulator, cation‐chloride cotransporters, voltage‐gated chloride channels, and chloride‐anion exchangers. As the collective understanding of Cl−transport processes continues to expand, investigators are equipped to more precisely characterize how endocrine factors promote hydromineral balance. We, therefore, conclude our discussion by paying special attention to recently defined roles for prolactin and corticosteroids in the regulation of Cl−transport in basal and derived clades.more » « less
