Layered phosphorus-like GeP5: a promising anode candidate with high initial coulombic efficiency and large capacity for lithium ion batteriesElectronic supplementary information (ESI) available. See DOI: 10.1039/c5ee02524a

• Main Authors: Li, Wenwu, Li, Huiqiao, Lu, Zhijuan, Gan, Lin, Ke, Linbo, Zhai, Tianyou, Zhou, Haoshen
• Format: Article
• Language: English
• ISSN: 1754-5692; 1754-5706
• DOI: 10.1039/c5ee02524a

In this work, we for the first time investigate GeP 5 as an anode material for lithium ion batteries (LIBs). Using a facile high energy mechanical ball milling (HEMM) method, we successfully synthesize pure GeP 5 and GeP 5 /C nanocomposite at ambient temperature and pressure. According to XRD Rietveld refinement and first principle calculations, GeP 5 possesses a two-dimensional layered structure similar to that of black P and graphite, and a high conductivity that is 10 000 and 10 times that of black P and graphite, respectively. Serving as novel anode materials, both GeP 5 and its carbon composite deliver an unprecedented high reversible capacity of ca. 2300 mA h g −1 , combined with a high initial coulombic efficiency of ca. 95%. Ex situ XRD and CV tests demonstrate that GeP 5 undergoes conversion and alloying type lithium storage mechanism and that its capacity is co-contributed to by both the Ge and P components. In addition, GeP 5 /C exhibits superior cycle stability and excellent high-rate performance with a capacity of 2127 mA h g −1 at 5 A g −1 . These properties suggest the promising application of these anode materials in next-generation high-energy and high-power LIBs. Layer structured GeP 5 is firstly developed as an anode material for LIB, it delivers a reversible capacity of 2300 mA h g −1 with a very high initial coulombic efficiency of 95%.