Flower-to-petal structural conversion and enhanced interfacial storage capability of hydrothermally crystallized MnCO3via the in situ mixing of graphene oxide

Abstract

Graphene oxide (GO) possesses high electron conductivity and good chemical-binding ability and thus can be used as a multifunctional additive for the preparation and application of electrode materials. As for the hydrothermal crystallization of MnCO₃ herein, the absence of GO causes the formation of MnCO₃ flower-like architectures composed of secondary spindles, while the presence of GO induces the flower-to-petal structural conversion and results in MnCO₃ spindle–GO composites. When applied as Li-ion battery anodes, the composite electrode delivers an initial coulombic efficiency (CE) of 71% and a reversible capacity of 1474 mA h g⁻¹ in the 400th cycle, much higher than those of MnCO₃ flowers (the initial CE ∼ 58%, the 400th capacity ∼ 1095 mA h g⁻¹) operated under the same conditions. In particular, the combination of discharging behavior and its differential capacity profile has been successfully used to estimate the interfacial contribution fraction (42%) of the whole reversible capacity (i.e., 1474 mA h g⁻¹) enhanced by the in situ mixing of 8.3 wt% GO.