NiCo 2 O 4 Particles with Facile PPy Modification as an Anode Material for High‐Performance Lithium‐Ion Batteries

A novel structure of “sea urchin‐like” NiCo 2 O 4 particles coated with a PPy protection layer is successfully synthesized via a hydrothermal method combined with a subsequent in situ polymerization. As a potential anode material for Li‐ion batteries, the as‐prepared NiCo 2 O 4 @PPy nanocomposite exhibits a high initial discharge capacity of 1524.1 mAh·g −1 and still maintains a wonderful reversible capacity of 955.6 mAh·g −1 over 100 cycles at a current density of 100 mA·g −1 , and it also delivers a very stable reversible capacity of 541 mAh·g −1 even at a high current density up to 1000 mA·g −1 . The excellent cyclability and rate capability of the composite might be ascribed to the unique architecture of NiCo 2 O 4 particles, especially for the in situ polymerized PPy conductive protection layers, which not only promote the anode material's conductivity, but also protect the inner NiCo 2 O 4 particles from mechanical damage in the process of discharging and charging. The present work indicates that PPy modification could be an effective direction to improve the electrochemical properties of anode with poor conductivity.