Mussel-inspired polydopamine treated Si/C electrode as high-performance anode for lithium-ion batteries

In this paper, we report a mussel-inspired polydopamine coating on the Si/C electrode via a simple immersion process to improve the electrochemical performance such as cycle stability and rate capability. The nanometer-thick polydopamine coating layer enables fast Li + transport at the interfaces and takes part in the formation of SEI due to the electron-rich amine group. The PD coated Si/C electrode exhibits good performance in long cycling test. Compare with the uncoated Si/C electrode, the capacity retention of the coated electrode is improved from 59.5% to 80% after 200 cycles. X-ray photoelectron spectroscopy, transmission electron microscopy and scanning electron microscopy prove that PD coating really promotes the formation of uniform and dense SEI and reduces cracks on the electrode surface. Meanwhile, the pulverization of electrodes which breaks the electrical contact with the current collector is alleviated.