A Schiff based p-phenylenediimine polymer as high capacity anode materials for stable lithium ion batteries

Compared with traditional inorganic graphite anode material, redox active organic compounds have great potential as anodes for high energy density lithium ion batteries (LIBs). The redox entities consisting of two Schiff bases on a benzene ring has been reported to exhibit high electrochemical activity for lithium ion storage. Schiff base materials with benzene ring are chemically stable, facile to synthesize and the raw materials are inexpensive and readily available. A linear type poly-Schiff base [C6H4N=CHCH=N]n (PDA-GO), prepared from simple aldol condensation reaction between p-phenylenediamine (PDA) and glyoxal (GO), was used as an anode material in CR2016 coin-type cells with lithium metal as the counter electrode. The organic anode based on PDA-GO for LIBs was found to exhibit good a high reversible specific capacity of 546 mAh g−1 at a current density of 100 mA g−1, excellent rate capabilities and ultra-stable cycling performance with high capacity retention of 70% up 600 cycles. The effect of temperature on the electrochemical performance of the PDA-GO anode material was examined and found that the specific capacity of the anode material is quite sensitive to temperature. Furthermore, the lithium storage mechanism of the PDA-GO anode material was investigated by cyclic voltammetry and FT-IR spectroscopy. These results indicate that the poly-Schiff base PDA-GO being a good anode material with competitive advantages of high capacity in comparison to graphite anode material.