Performance of electroless-plated lithium titanate/copper composites as anode materials in 18650-type lithium-ion batteries

Commercial lithium titanate (Li4Ti5O12) has been modified with nanosize Cu layer generated by electroless plating. X-ray diffractometry, Raman spectroscopy, scanning and transmission electron microscopy were applied to characterize the microstructure and morphology of the material. The electrochemical performance of the Cu-modified composites (Li4Ti5O12/Cu) was examined using 18650-type full batteries. The composites exhibited excellent rate performance and cycling stability. Mean discharge voltage of the battery greatly increased, its surface temperature decreased, and its capacity retention improved from 78.4 to 87.9 % after 8000 cycles at 25 A degrees C at 3 C rate. These improvements may be attributed to the decrease in electrochemical polarization after Cu coating on surface as verified by cyclic voltammetry and electrochemical impedance spectroscopy in coin cells, and a severance of direct contact between LTO particles and electrolyte also made differences.