Polypyrrole-iron-oxygen coordination complex as high performance lithium storage material

Current lithium ion battery (LIB) technologies are all based on inorganic electrodes though organic materials have been hyped as electrodes for years. Disadvantages such as low specific capacity and poor rate performance hinder their applications. Here we report a novel high-performance organometallic lithium-storage material, a polypyrrole-iron-oxygen (PPy-Fe-O) coordination complex. Extended X-ray absorption fine structure (EXAFS) spectroscopy and density functional theory (DFT) calculations indicate that this complex has a multilayer structure. The strong and stable intralayer Fe-N coordination permits the material to possess high specific capacity, the high reversibility of its interlayer Fe-O-Fe interaction during cycling ensures its high cycling stability and the conducting PPy matrix endows it with outstanding rate performance. These findings pave the way to constructing a new type of high-performance organic anode materials for LIBs.