High-Entropy Engineering of Cubic SiP with Metallic Conductivity for Fast and Durable Li-Ion Batteries.

A cost-effective, scalable ball milling process is employed to synthesize the InGeSiP3 compound with a cubic ZnS structure, aiming to address the sluggish reaction kinetics of Si-based anodes for Lithium-ion batteries (LIBs). Experimental measurements and first-principles calculations confirm that the synthesized InGeSiP3 exhibits significantly higher electronic conductivity, larger Li-ion diffusivity, and greater tolerance to volume change than its parent phases InGe (or Si)P2 or In (or Ge, or Si)P. These improvements stem from its elevated configurational entropy. Multiple characterizations validate that InGeSiP3 undergoes a reversible Li-storage mechanism that involves intercalation, followed by conversion and alloy reactions, resulting in a reversible capacity of 1,733 mA h g-1 with an initial Coulombic efficiency of 90%. Moreover, the InGeSiP3-based electrodes exhibit exceptional cycling stability, retaining a 1,121 mA h g-1 capacity with a retention rate of ∼87% after 1,500 cycles at 2,000 mA g-1 and remarkable high-rate capability, achieving 882 mA h g-1 at 10,000 mA g-1. Inspired by the distinctive characteristic of high entropy, we extend our synthesis to high entropy GaCu (or Zn)InGeSiP5, CuZnInGeSiP5, GaCuZnInGeSiP6, InGeSiP2S (or Se), and InGeSiPSSe. This endeavor overcomes the immiscibility of different metals and non-metals, paving the way for electrochemical energy storage application of high-entropy silicon-phosphides. This article is protected by copyright. All rights reserved.