Hierarchical architectured MnCO3 microdumbbells: facile synthesis and enhanced performance for lithium ion batteries

Abstract

Hierarchical architectured MnCO₃ microdumbbells and lamellar structured MnCO₃ nanosheets were selectively synthesized by a facile reflux route. Hierarchical architectured MnCO₃ microdumbbells (approximately 0.5–1.5 μm in length and 0.3–0.9 μm in width) were composed of nanoparticles, while the lamellar structured MnCO₃ nanosheets had uniform length of approximately 400 nm. Both structures were employed as anode active materials in lithium ion batteries. Experimental results showed that the hierarchical architectured MnCO₃ microdumbbells exhibited superior electrochemical performances compared with the lamellar structured MnCO₃ nanosheets. At a current rate of 0.5 C, the reversible capacity of the hierarchical architectured MnCO₃ microdumbbell electrode after 100 cycles was 775 mA h g⁻¹, while the lamellar structured MnCO₃ nanosheets electrode was only 50 mA h g⁻¹ after 100 cycles. The superior electrochemical behavior of hierarchical architectured MnCO₃ microdumbbell materials could be ascribed to the unique micro-nano assembly structure, simultaneously cushioning the volume change, maintaining the electrode integrity, and offering a short diffusion distance.