High-Performance Phosphorus-Graphite Dual-Ion Battery

Recently, dual-ion batteries (DIBs) are regarded as a promising alternative to well-developed lithium-ion batteries, and the development of high-performance and abundant-sodium-based DIBs (SDIBs) is being intensively pursued. In this work, a novel SDIB composed of a phosphorus (P)-based anode and graphite (G) cathode is successfully constructed for the first time. This P-G SDIB shows a high working voltage of around 3.9 V, a high reversible capacity of 373 mA h/g, good rate capability, and long cyclability, which are superior to those of the most reported DIBs. The ex situ X-ray diffraction, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy tests reveal the insertion/extraction mechanism of Na+ ions into/from P-based anodes via reversible Na-P alloying reactions accompanied with high charge-storage capability. Moreover, the presodiation of P-based composites is found to be an efficient approach to boost the cycling performance of the P-G SDIB by forming a stable NaF-rich solid electrolyte interphase layer to alleviate electrolyte decomposition. Our results demonstrate that P-based SDIBs possess tremendous potential for practical electrochemical energy-storage applications.