Ultrafine FeS2 nanocrystals/porous nitrogen doped carbon
Ultrafine FeS 2 nanocrystals/porous nitrogen doped carbon hybrid nanospheres encapsulated in three dimensional graphene for simultaneous efficient lithium and sodium ion storage† Zhonghui Chen ‡ ab Shuo Li ‡ c Yong Zhao a Mohamed F Aly Aboud d Imran Shakir d and Yuxi Xu b