The preparation and electrochemical storage behavior of MoS2 nanodots--more precisely single-layered ultrasmall nanoplates--embedded in carbon nanowires has been studied. The preparation is achieved by an electrospinning process that can be easily scaled up. The rate performance and cycling stability of both lithium and sodium storage were found to be outstanding. The storage behavior is, moreover, highly exciting from a fundamental point of view, as the differences between the usual storage modes--insertion, conversion, interfacial storage--are beneficially blurred. The restriction to ultrasmall reaction domains allows for an almost diffusion-less and nucleation-free "conversion", thereby resulting in a high capacity and a remarkable cycling performance.

Zn metal has been considered as a promising anode material for rechargeable aqueous metal-ion batteries. However, the propensity of dendrite growth during plating restricts its practical applications. Herein we propose an effective, low-cost, and nontoxic electrolyte additive, tetrabutylammonium sulfate (TBA2SO4), as the first example of a cationic surfactant-type electrolyte additive in Zn-ion batteries, which can induce the uniform Zn deposition in both electrode preparation and the battery charge/discharge process. Electrochemical characterizations, in situ optical microscopy observation, along with density functional theory (DFT) calculations reveal the unique zincophobic repulsion mechanism, which results in the minimum addition amount of 0.029 g L–1 compared with other reported additives (at least 1g L–1), demonstrating the great potential for practical application. Excellent cycling performance with dendrite-free morphology at different current densities and discharge depths is achieved for both the symmetric cell and the full cell (coupled to α-MnO2) using the as-prepared 3D Zn anode and the proposed additives.

Sodium-ion batteries (SIBs) have attracted increasing attention in the past decades, because of high overall abundance of precursors, their even geographical distribution, and low cost. Apart from inherent thermodynamic disadvantages, SIBs have to overcome multiple kinetic problems, such as fast capacity decay, low rate capacities and low Coulombic efficiencies. A special case is sodium super ion conductor (NASICON)-based electrode materials as they exhibit - besides pronounced structural stability - exceptionally high ion conductivity, rendering them most promising for sodium storage. Owing to the limiting, comparatively low electronic conductivity, nano-structuring is a prerequisite for achieving satisfactory rate-capability. In this review, we analyze advantages and disadvantages of NASICON-type electrode materials and highlight electrode structure design principles for obtaining the desired electrochemical performance. Moreover, we give an overview of recent approaches to enhance electrical conductivity and structural stability of cathode and anode materials based on NASICON structure. We believe that this review provides a pertinent insight into relevant design principles and inspires further research in this respect.

Three‐dimensional macroporous silicon (see image) was synthesized by a magnesiothermic reduction method as an anode material for lithium ion batteries. An improved lithium storage performance was obtained after coating silver nanoparticles on the surface of the silicon. The silver‐coated 3D macroporous silicon shows promise as an anode material in lithium ion batteries.

Sodium ion batteries are one of the realistic promising alternatives to the lithium analogues. However, neither theoretical energy/power density nor the practical values reach the values of Li cathodes. Poorer performance is expected owing to larger size, larger mass, and lower cell voltage. Nonetheless, sodium ion batteries are considered to be practically relevant in view of the abundance of the element Na. The arguments in favor of Li and to the disadvantage of Na would be completely obsolete if the specific performance data of the latter would match the first. Here we present a cathode consisting of carbon-coated nanosized Na3V2(PO4)3 embedded in a porous carbon matrix, which not only matches but even outshines lithium cathodes under high rate conditions. It can be (dis)charged in 6 s with a current density as high as 22 A/g (200 C), still delivering a specific capacity of 44 mAh/g, while up to 20 C, the polarization is completely negligible.