Highly Efficient Na+ Storage in Uniform Thorn Ball-Like α-MnSe/C Nanospheres

Abstract

Because of its high theoretical capacity, MnSe has been identified as a promising candidate as the anode material for sodiumion batteries. However, its fast capacity deterioration due to the huge volume change during the intercalation/deintercalation of sodium ions severely hinders its practical application. Moreover, the sodium storage mechanism of MnSe is still under discussion and requires in-depth investigations. Herein, the unique thorn ball-like α-MnSe/C nanospheres have been prepared using manganese-containing metal organic framework (Mn-MOF) as a precursor followed by in situ gas-phase selenization at an elevated temperature. When serving as the anode material for sodium-ion battery, the as-prepared α-MnSe/C exhibits enhanced sodium storage capabilities of 416 and 405 mAh g −1 at 0.2 and 0.5 A g −1 after 100 cycles, respectively. It also shows a superior capacity retention of 275 mA h g −1 at 10 A g −1 after 2000 cycles, and a rate performance of 279 mA h g −1 at 20 A g −1 . Such sodium storage properties could be attributed to the unique structure offering a highly efficient Na + diffusion kinetics with a diffusion coefficient between 1 × 10 -11 and 3 × 10 -10 cm 2 s −1 . The density functional theory calculation indicates that the fast Na + diffusion mainly takes place on the (100) plane of MnSe along a V-shaped path because of a relatively low diffusion energy barrier of 0.15 eV.

Bilateral Interfaces in In2Se3-CoIn2-CoSe2 Heterostructures for High-Rate Reversible Sodium Storage

“…Meanwhile, the diffusion coefficients of Na + in our electrodes were measured by the Galvanostatic Intermittent Titration Technique (GITT) and could be calculated based on a simplified equation 57,58 i k j j j j j y…”

“…Meanwhile, the diffusion coefficients of Na + in our electrodes were measured by the Galvanostatic Intermittent Titration Technique (GITT) and could be calculated based on a simplified equation , where Δ E s is the potential change (V) due to the current pulse, Δ E t stands for the potential change (V) during the galvanostatic discharge after eliminating the i R drop, L is the Na + diffusion length, which could be simply taken as the thickness of the electrode, and τ represents the relaxation time (s). The GITT curves and the corresponding D values of the discharge and charge processes are shown in Figure e.…”

A core@double‐shell structured silicon/ flower‐like manganese selenide/carbon composite as superior dual anode materials of Li/Na‐ion batteries

“…In order to enhance the electrochemical performance of MnSe based composite, the conventional method is to compound with carbon material. However, when composite with carbon material, the form of MnSe in the product is mostly nanoparticles 17,37,44,54‐57 . Because the particle size is small and evenly dispersed on the matrix of carbon material, the electrochemical performance is significantly improved.…”

Multifunctional sandwich-structured double-carbon-layer modified SnS nanotubes with high capacity and stability for Li-ion batteries

“…Third, irrespective of whether a conversion reaction or an alloying reaction occurs, SnS will produce large volume strain in the electrochemical process, including electrode particle pulverization, deterioration or agglomeration, resulting in poor cycle performance. 11 Relevant approaches are adopted to address these problems, such as combining with carbon materials, [12][13][14][15] preparing nano hollow structures, 7 doping and modification of heteroatoms. [16][17][18] Carbon materials can play an important role in buffering volume change, enhancing ion and electron transport and reducing the size of anode materials by constructing a reasonable structure.…”