MOFs as reactant: In situ synthesis of Li2ZnTi3O8@C–N nanocomposites as high performance anodes for lithium-ion batteries

Abstract

Lithium zinc titanate (Li2ZnTi3O8) is a desirable anode material for lithium-ion batteries (LIBs) due to its low cost, non-toxicity and high safety. However, the low electronic conductivity and inferior rate capability hinder the commercial application of Li2ZnTi3O8. Carbon coating can not only effectively enhance the electronic conductivity of Li2ZnTi3O8 but also suppress the growth of particle size in the sintering process. In addition, carbon can provide extra capacity when using Li2ZnTi3O8/C as an anode. Here, a simple yet powerful strategy is introduced to in situ prepare nitrogen-doped carbon coating on Li2ZnTi3O8 nanoparticles using ZIF-8 as carbon, nitrogen and zinc sources. After sintering at 700°C the obtained nanocomposite shows large discharge specific capacity of 287.3mAhg−1 at 0.5Ag−1, excellent cycling stability (>90% capacity retention after 200cycles corresponding to the largest value at 2Ag−1) and outstanding rate capability at 4 and 5Ag−1. These properties, combined with its high safety and ease of fabrication, make such Li2ZnTi3O8@C–N nanocomposite an ideal anode candidate for LIBs.