Layered Oxysulfides Sr₂MnO₂Cu_2m-0.5S_m+1 (m = 1, 2, and 3) as Insertion Hosts for Li Ion Batteries

Abstract

The layered oxysulfides Sr2MnO2Cu2m-0.5Sm+1 (m = 1-3) consist of alternating perovskite-type Sr2MnO2 layers and copper sulfide layers. The copper ions can be replaced electrochemically and reversibly by Li. The lithiated materials were studied by Li MAS NMR, and Li resonances were observed with shifts that could be rationalized based on the number of sulfide layers. The materials were cycled versus Li and showed enhanced capacity retention in comparison to pure Cu2S; the good electrochemical performance was ascribed to the presence of the layered framework structure and rapid Li+ and Cu+ conductivity in the sulfide layers.

Beyond Intercalation‐Based Li‐Ion Batteries: The State of the Art and Challenges of Electrode Materials Reacting Through Conversion Reactions

“…[ 209 ] As in the case of the other sulfi des reviewed so far, Cu 2 S behaves poorly, the initial capacity dropping to negligible values in less than 20 cycles. [ 213 ] …”

Influence of the Morphology of Lithiated Copper(I) Sulfides with the Formal Composition “Li2Cu4S3” on Their Stability in Electrochemical Cycling

“…[13] In a similar approach thermal degradation of the copper sulfide cluster anions [Cu 4 (SPh) 6 ] 2-and [Cu 5 -(SPh) 7 ] 2-was found to give Cu 1.96 S. [14] However, the electrochemical conversion of Cu 2-x S (x = 0 and 0.24) to Li 2 S and Cu has been shown to be only poorly reversible with the initial capacity dropping to negligible values in less than 20 cycles. [15] Therefore, we intended to synthesize nanostructured lithiated copper(I) sulfides by thermal decomposition of related cluster molecules. Upon electrochemical removal of the lithium ions (charging) in the first step, this material should yield "in situ" Cu II S. Here, we report on the syntheses and different electrochemical behaviour of lithiated copper(I) sulfide of formal composition "Li 2 Cu 4 S 3 " synthesized either by the thermolysis of molecular cluster precursor compounds or by the solid-state reaction of Li 2 S and Cu 2 S. Ionic compound 1 crystallizes as a mixture of crystals in two different space groups, namely, in the monoclinic space group P2 1 /c (1b) and triclinic P1 (1a; Table 1).…”

A Polyaniline‐Intercalated Layered Manganese Oxide Nanocomposite Prepared by an Inorganic/Organic Interface Reaction and Its High Electrochemical Performance for Li Storage

“…[7,8] As an important functional material with wide applications (e.g., in catalysts, magnetic materials, ion-sieves, supercapacitors, batteries, and others), manganese oxides have been widely studied over the past decades. [9][10][11][12][13][14] In recent years, many efforts have been devoted to intercalate guest organic molecules (e.g., molecular or polymer) into layered manganese oxides, because the novel structure of intercalated layered manganese oxide can provide unique functions that can not be achieved by using conventional manganese oxides. [15][16][17][18][19][20][21] The typical preparation methods consists of several steps and is complicated: [15][16][17][18][19][20][21] i) The layered manganese oxide (or Birnessite-type manganese oxide) A x MnO 2 (where A is K, Na, etc.)…”