Design of cobalt-based metal-organic frameworks like solid electrolyte interphase (SEI) film for chemically stable graphite anode of lithium-ion batteries

Abstract

As an anode material of lithium-ion battery, it usually has a high specific capacity, but poor cycle stability always restricts its development. In this paper, the most ordinary graphite anode is modified by cobalt-based metal-organic frameworks (Co-MOFs). It can be noted that Co-MOF coating on graphite surface can form like solid electrolyte interphase (SEI) film, and the crystalline planes and defects also have slight transformations. Electrochemical test results illustrate that the anodes with graphite modified by 15% Co-MOF for lithium-ion batteries have reversible lithiation and delithiation processes, the low charge transfer resistance, and fast lithium-ion diffusion rate due to the electrochemical reactions on some limited graphite crystal planes. Charge and discharge test results display that the initial discharge specific capacity at 100, 200, and 300 mA g−1 can reach 368.92, 290.06, and 268.99 mAh g−1, respectively. And after 50 cycles, the capacity retention rate is higher than 80%.