No abstract

No abstract

Heterostructure construction is an efficient method for reinforcing K+ storage of transition metal selenides. The spontaneously developed internal electric fields give a strong boost to charge transport and significantly reduce the activation energy. Nevertheless, perfection of the interfacial region based on the energy level gradient and lattice matching degree is still a great challenge. Herein, rich vacancies and ultrafine CoSe2–FeSe2 heterojunctions with semicoherent phase boundary are simultaneously obtained, which possess unique electronic structures and abundant active sites. When employed as anodes for potassium‐ion batteries (PIBs), CoSe2–FeSe2@C composites display a reversible potassium storage of 401.1 mAh g−1 at 100 mA g−1 and even 275 mAh g−1 at 2 A g−1. Theoretical calculation also reveals that the potassium‐ion diffusion can be dramatically promoted by the controllable CoSe2–FeSe2 heterojunction.

No abstract

Herein, the quantum dots-assisted self-assembly MoSe2-MoO3 with a porous structure is synthesized via a MOFs-directed strategy involving a thermal-induced reaction with Se. As an anode material for sodium ion batteries,...

No abstract

An interlayer has been regarded as a promising mediator to prolong the life span of lithium sulfur batteries because its excellent absorbability to soluble polysulfide efficiently hinders the shuttle effect. Herein, we designed various interlayers and understand the working mechanism of an interlayer for lithium sulfur batteries in detail. It was found that the electrochemical performance of a S electrode for an interlayer located in cathode side is superior to the pristine one without interlayers. Surprisingly, the performance of the S electrode for an interlayer located in anode side is poorer than that of pristine one. For comparison, glass fibers were also studied as a nonconductive interlayer for lithium sulfur batteries. Unlike the two interlayers above, these nonconductive interlayer did displays significant capacity fading because polysulfides were adsorbed onto insulated interlayer. Thus, the nonconductive interlayer function as a "dead zone" upon cycling. Based on our findings, it was for the first time proposed that a controllably optimized interlayer, with electrical conductivity as well as the absorbability of polysulfides, may function as a "vice-electrode" of the anode or cathode upon cycling. Therefore, the cathodic conductive interlayer can enhance lithium sulfur battery performance, and the anodic conductive interlayer may be helpful for the rational design of 3D networks for the protection of lithium metal.

The high‐rate cyclability of Li‐rich Mn‐based oxide (LMO) is highly limited by the electrochemical polarization resulting from the slow kinetic of the Li2MnO3 phase. Herein, the Prussian blue (PB) coating layer with specific redox potential is introduced as a functionalized interface to overcome the side effect and the escaping of O on the surface of LMO, especially its poor rate capability. In detail, the PB layer can restrict the large polarization of LMO by sharing overloaded current at a high rate due to the synchronous redox of PB and LMO. Consequently, an enhanced high rate performance with capacity retention of 87.8% over 300 cycles is obtained, which is superior to 50.5% of the pristine electrode. Such strategies on the high‐rate cyclability of Li‐rich Mn‐based oxide compatible with good low‐rate performances may attract great attention for pursuing durable performances.