Developing Polymer Cathode Material for the Chloride Ion Battery

The chloride ion battery is an attractive rechargeable battery owing to its high theoretical energy density and sustainable components. An important challenge for research and development of chloride ion batteries lies in the innovation of the cathode materials. Here we report a nanostructured chloride ion-doped polymer, polypyrrole chloride, as a new type of potential cathode material for the chloride ion battery. The as-prepared polypyrrole chloride@carbon nanotubes (PPyCl@CNTs) cathode shows a high reversible capacity of 118 mAh g^–1 and superior cycling stability. Reversible electrochemical reactions of the PPyCl@CNTs cathode based on the redox reactions of nitrogen species and chloride ion transfer are demonstrated. Our work may guide and offer electrode design principles for accelerating the development of rechargeable batteries with anion transfer

Stereoselective Sequential [4+2]/[2+2] Cycloadditions Involving 2‑Alkenylindolenines: An Approach to Densely Functionalized Benzo[<i>b</i>]indolizidines

A stereoselective sequential [4+2]/[2+2] cycloaddition process involving 2-alkenylindolenines has been developed. This unprecedented protocol allows a rapid access to densely functionalized benzo­[<i>b</i>]­indolizidines containing a fully substituted piperidine ring with five contiguous stereogenic centers in good yields with excellent diastereoselectivities. This finding demonstrated the unique synthetic utility of the 2-alkenylindolenine species in the construction of complex polycyclic <i>N</i>-heterocycles

Stereoselective Sequential [4+2]/[2+2] Cycloadditions Involving 2‑Alkenylindolenines: An Approach to Densely Functionalized Benzo[<i>b</i>]indolizidines

A stereoselective sequential [4+2]/[2+2] cycloaddition process involving 2-alkenylindolenines has been developed. This unprecedented protocol allows a rapid access to densely functionalized benzo­[<i>b</i>]­indolizidines containing a fully substituted piperidine ring with five contiguous stereogenic centers in good yields with excellent diastereoselectivities. This finding demonstrated the unique synthetic utility of the 2-alkenylindolenine species in the construction of complex polycyclic <i>N</i>-heterocycles

Nanostructured cation disordered Li₂FeTiO₄/graphene composite as high capacity cathode for lithium-ion batteries

<p>Nanostructured Li₂FeTiO₄/graphene composite with a cation disordered rock salt structure (Fm-3 m) has been synthesised via a solgel process using graphene oxide (GO) as a template. The as-prepared Li₂FeTiO₄ nanoparticles with a particle size of 20–50 nm are uniformly distributed on the graphene substrate. The Li₂FeTiO₄/graphene cathode shows phase transformations of Fe²⁺/Fe³⁺ and Fe³⁺/Fe⁴⁺ in a wide potential range from 1.5 to 5.0 V and possesses a high discharge capacity of 218.6 mAh g⁻¹ (equivalent to 1.4 Li per formula unit). A reversible capacity of 176.9 mAh g⁻¹ is maintained after 50 cycles. High capacity retention rate at 1C after 200 cycles is obtained. The Li₂FeTiO₄/graphene should be of great interest as a potential cathode material for high-performance lithium-ion batteries.</p

Vanadium Oxychloride/Magnesium Electrode Systems for Chloride Ion Batteries

We report a new type of rechargeable chloride ion battery using vanadium oxychloride (VOCl) as cathode and magnesium or magnesium/magnesium chloride (MgCl₂/Mg) as anode, with an emphasis on the VOCl-MgCl₂/Mg full battery. The charge and discharge mechanism of the VOCl cathode has been investigated by X-ray diffraction, X-ray photoelectron spectroscopy, and electrochemical measurements, demonstrating the chloride ion transfer during cycling. The VOCl cathode can deliver a reversible capacity of 101 mAh g^–1 at a current density of 10 mA g^–1 and a capacity of 60 mAh g^–1 was retained after 53 cycles in this first study

Magnesium Anode for Chloride Ion Batteries

A key advantage of chloride ion battery (CIB) is its possibility to use abundant electrode materials that are different from those in Li ion batteries. Mg anode is presented as such a material for the first time and Mg/C composite prepared by ball milling of Mg and carbon black powders or thermally decomposed MgH₂/C composite has been tested as anode for CIB. The electrochemical performance of FeOCl/Mg and BiOCl/Mg was investigated, demonstrating the feasibility of using Mg as anode

Stereoselective Sequential [4+2]/[2+2] Cycloadditions Involving 2‑Alkenylindolenines: An Approach to Densely Functionalized Benzo[<i>b</i>]indolizidines

A stereoselective sequential [4+2]/[2+2] cycloaddition process involving 2-alkenylindolenines has been developed. This unprecedented protocol allows a rapid access to densely functionalized benzo­[<i>b</i>]­indolizidines containing a fully substituted piperidine ring with five contiguous stereogenic centers in good yields with excellent diastereoselectivities. This finding demonstrated the unique synthetic utility of the 2-alkenylindolenine species in the construction of complex polycyclic <i>N</i>-heterocycles

Stereoselective Sequential [4+2]/[2+2] Cycloadditions Involving 2‑Alkenylindolenines: An Approach to Densely Functionalized Benzo[<i>b</i>]indolizidines

A stereoselective sequential [4+2]/[2+2] cycloaddition process involving 2-alkenylindolenines has been developed. This unprecedented protocol allows a rapid access to densely functionalized benzo­[<i>b</i>]­indolizidines containing a fully substituted piperidine ring with five contiguous stereogenic centers in good yields with excellent diastereoselectivities. This finding demonstrated the unique synthetic utility of the 2-alkenylindolenine species in the construction of complex polycyclic <i>N</i>-heterocycles

Nanoconfined Iron Oxychloride Material as a High-Performance Cathode for Rechargeable Chloride Ion Batteries

As a group of attractive photoelectromagnetic and catalytic functional materials, metal oxychlorides have been attracting attention for electrochemical energy storage in rechargeable chloride ion battery (CIB) systems recently. Their application, however, is limited by the complicated synthesis and/or poor cycling stability. Herein, a facile strategy using vacuum impregnation and subsequent thermal decomposition at mild conditions has been developed to synthesize the FeOCl/CMK-3 nanocomposite material. Benefiting from the nanoconfined structure, a high-performance FeOCl/CMK-3 cathode, which has a high discharge capacity of 202 mAh g^–1, superior cycling stability, and significantly improved charge transfer and chloride ion diffusion, is achieved. The electrolyte component is found to show a high affinity with the chlorine layer in the FeOCl phase, inducing evident expansion of the FeOCl layers along the <i>b</i>-axis direction and thus boosting a new potential liquid exfoliation approach for preparing 2D FeOCl material. Importantly, reversible electrochemical reactions of the FeOCl cathode material based on the redox reactions of iron species and chloride ion transfer are revealed

Synthesis and Electrocatalytic Property of Diiron Hydride Complexes Derived from a Thiolate-Bridged Diiron Complex

Interaction of a diiron thiolate-bridged complex, [Cp*Fe­(μ-η²:η⁴-bdt)­FeCp*] (<b>1</b>) (Cp* = η⁵-C₅Me₅; bdt = benzene-1,2-dithiolate) with a proton gives an Fe^IIIFe^III hydride bridged complex, [Cp*Fe­(μ-bdt)­(μ-H)­FeCp*]­[BF₄] (<b>3­[BF</b>_<b>4</b><b>]</b>). According to <i>in situ</i> variable temperature ¹H NMR studies, the formation of <b>3­[BF</b>_<b>4</b><b>]</b> was evidenced to occur through a stepwise pathway: protonation occurring at an iron center to produce terminal hydride [Cp*Fe­(μ-bdt)­(<i>t</i>-H)­FeCp*]­[BF₄] (<b>2</b>) and subsequent intramolecular isomerization to bridging hydride <b>3­[BF</b>_<b>4</b><b>]</b>. A one-electron reduction of <b>3­[BF</b>_<b>4</b><b>]</b> by CoCp₂ affords a paramagnetic mixed-valent Fe^IIFe^III hydride complex, [Cp*Fe­(μ-η²:η²-bdt)­(μ-H)­FeCp*] (<b>4</b>). Further, studies on protonation processes of diruthenium and iron–ruthenium analogues of <b>1</b>, [Cp*M1­(μ-bdt)­M2Cp*] (M1 = M2 = Ru, <b>5</b>; M1 = Fe, M2 = Ru, <b>8</b>), provide experimental evidence for terminal hydride species at these bdt systems. Importantly, diiron or diruthenium hydride bridged complexes <b>3­[BF</b>_<b>4</b><b>]</b>, <b>7­[BF</b>_<b>4</b><b>]</b> and iron–ruthenium heterodinuclear complex <b>8­[PF</b>_<b>6</b><b>]</b> can realize electrocatalytic hydrogen evolution