Sodiation–Desodiation Reactions of Various Binary Phosphides as Novel Anode Materials of Na-Ion Battery

Abstract

Sodiation−desodiation behaviors were investigated for electrodes composed of various binary phosphides, InP, CuP 2 , GeP, SiP, and LaP, as anode materials of a Na-ion battery. Although LaP electrode did not react with Na, the other electrodes showed reversible sodiation− desodiation reactions in the initial cycles. Rapid capacity decays were observed for CuP 2 , GeP, and SiP electrodes. In contrast, a better cyclability was attained for the InP electrode. These results indicate that binary phosphides (M−P) require four properties for improving cyclability: (i) low thermodynamic stability of M−P, (ii) high electronic conductivity of M, (iii) low hardness of M, and (iv) reactivity of M with Na.

Advances in sodium secondary batteries utilizing ionic liquid electrolytes

“…A variety of binary phosphides (GeP 5 , GeP, SiP, LaP, InP, and CuP 2 ) were evaluated in 1 mol dm À3 Na[FSA]-[C 3 C 1 pyrr][FSA] at 30 1C. 368 The best cycleability was observed for InP, which was attributed to the provision of electronic conductivity and maintenance of interparticle contact by the adjustment of NaIn morphology in response to volume expansion by Na 3 P.…”

Optimization of the Carbon Content in Copper Phosphide–Carbon Composites for High Performance Sodium Secondary Batteries Using Ionic Liquids

“…Indeed, negative electrode materials have received growing attention during the development of NIBs, with high gravimetric and volumetric capacities being targeted. For example, metal phosphides are known to provide high theoretical gravimetric capacities (∼1131 mAh g −1 for Sn 4 P 3 , ∼1292 mAh g −1 for CuP 2 , and ∼1493 mAh g −1 for NiP 3 ) owing to the large sodium intake through the formation of Na 3 P. However, large volume changes in the electrode during sodiation and desodiation are usually accompanied by pulverization of the active material, thereby resulting in capacity degradation . Although nano‐structuring and morphology optimization have been employed to address such issues, these techniques often involve low electrode mass loadings and difficult preparation methods, which are not suitable for practical purposes.…”

Sn4P3/SbSn Nanocomposites for Anode Application in Sodium‐Ion Batteries

“…∼0.94 V are observed. According to the literature,, peaks at ∼0.24, ∼0.37 V mainly come from desodiation of Na−Sn alloy while the rest originate from the desodiation of Na 3 P and Na 3 Sb. In the second and later cathodic cycles, three stable peaks at ∼0.53, ∼0.28, ∼0.02 V can be found, which are assigned to the stepwise sodiation of Sb, P and Sn.…”