CoPSe: A New Ternary Anode Material for Stable and High‐Rate Sodium/Potassium‐Ion Batteries

Abstract

The exploration of ideal electrode materials overcoming the critical problems of large electrode volume changes and sluggish redox kinetics induced by large ionic radius of Na+/K+ ions is highly desirable for sodium/potassium‐ion batteries (SIBs/PIBs) toward large‐scale applications. The present work demonstrates that single‐phase ternary cobalt phosphoselenide (CoPSe) in the form of nanoparticles embedded in a layered metal–organic framework (MOF)‐derived N‐doped carbon matrix (CoPSe/NC) represents an ultrastable and high‐rate anode material for SIBs/PIBs. The CoPSe/NC is fabricated by using the MOF as both a template and precursor, coupled with in situ synchronous phosphorization/selenization reactions. The CoPSe anode holds a set of intrinsic merits such as lower mechanical stress, enhanced reaction kinetics, as well as higher theoretical capacity and lower discharge voltage relative to its counterpart of CoSe2, and suppressed shuttle effect with higher intrinsic electrical conductivity relative to CoPS. The involved mechanisms are evidenced by substantial characterizations and density functional theory (DFT) calculations. Consequently, the CoPSe/NC anode shows an outstanding long‐cycle stability and rate performance for SIBs and PIBs. Moreover, the CoPSe/NC‐based Na‐ion full cell can achieve a higher energy density of 274 Wh kg−1, surpassing that based on CoSe2/NC and most state‐of‐the‐art Na‐ion full cells based on P‐, Se‐, or S‐containing binary/ternary anodes to date.

A Tandem Electrocatalysis of Sulfur Reduction by Bimetal 2D MOFs

“…It is worth noting that each of the 2p spin-orbit (Co 2p or Ni 2p) includes characteristic multiple satellite peaks, indicating the existence of unpaired valence electrons of the metal centers in the 2D MOF sheets. [34][35][36] In situ formation of sulfur onto CoNi-MOF results in downshift of the 2p spin-orbits compared to that of the CoNi-MOF (Figure 2a,b). Similarly, lower binding energies of the metal centers were also detected for the S@Co-MOF and S@Ni-MOF composites (Figure S6, Supporting Information).…”

A gradient hexagonal-prism Fe3Se4@SiO2@C configuration as a highly reversible sodium conversion anode

“…The continuously increasing popularization of electronic products and smart grids is appealing for viable and highefficiency energy storage devices. [1][2][3][4][5] Sodium ion batteries (SIBs) as a cost-effective and reliable supplement for new-style rechargeable batteries have shown remarkable and signicant competitiveness owing to the naturally abundant reserves and modest cost of sodium. [6][7][8][9][10][11][12][13][14][15] Moreover, the weaker Lewis acidity of Na + potentially endows it with faster ion/charge transfer kinetics and mobility in the electrode/electrolyte interface, thus manifesting a smaller Stokes radius and lower desolvation energy.…”

Water‐Soluble Salt Template‐Assisted Anchor of Hollow FeS2 Nanoparticle Inside 3D Carbon Skeleton to Achieve Fast Potassium‐Ion Storage

“…Potassium‐ion storage system, including potassium‐ion batteries (PIBs) and potassium‐ion hybrid capacitors (PIHCs), are attracting widespread attentions owing to the natural abundance of potassium resources and standard redox potential of K/K + (−2.92 V) close to that of Li/Li + (−3.04 V) in comparison to lithium‐ion storage system. [ 1–9 ] However, the lower reversible capacity and poor cycling stability of PIBs and PIHCs are still unsatisfactory to meet the requirements of high energy density and durable devices. Particularly, the larger intrinsic ionic radius of K + (1.38 Å), versus its counterpart Li + (0.76 Å), leads to sluggish reaction kinetics and serious mechanical stress/strain of host electrode materials.…”