Facile Synthesis of Hierarchical Micro/Nanostructured MnO Material and Its Excellent Lithium Storage Property and High Performance as Anode in a MnO/LiNi_(0.5)Mn_(1.5)O_(4-δ) Lithium Ion Battery

摘要

Hierarchical microanostructured MnO material is synthesized from a precursor of MnCO3 with olive shape that is obtained through a facile one-pot hydrothermal procedure. The hierarchical microanostructured MnO is served as anode of lithium ion battery together with a cathode of spinel LiNi_(0.5)Mn_(1.5)O_(4-δ) material, which is synthesized also from the precursor of MnCO3 with olive shape through a different calcination process. The structures and compositions of the as-prepared materials are characterized by TGA, XRD, BET, SEM, and TEM. Electrochemical tests of the MnO materials demonstrate that it exhibit excellent lithium storage property. The MnO material in a MnO/Li half cell can deliver a reversible capacity of 782.8 mAh g~(-1) after 200 cycles at a rate of 0.13 C, and a stable discharge capacity of 350 mAh g~(-1) at a high rate of 2.08 C. Based on the outstanding electrochemical property of the MnO material and the LiNi_(0.5)Mn_(1.5)O_(4-δ) as well, the Mn0/LiNi_(0.5)Mn_(1.5)O_(4-δ) full cell has demonstrated a high discharge specific energy ca. 350 Wh kg~(-1) after 30 cycles at 0.1 C with an average high working voltage at 3.5 V and a long cycle stability. It can release a discharge specific energy of 227 Wh kg~(-1) after 300 cycles at a higher rate of 0.5 C. Even at a much higher rate of 20 C, the MnO/LiNi_(0.5)Mn_(1.5)O_(4-δ) full cell can still deliver a discharge specific energy of 145.5 Wh kg~(-1). The excellent lithium storage property of the MnO material and its high performance as anode in the MnO/ LiNi_(0.5)Mn_(1.5)O_(4-δ) lithium ion battery is mainly attributed to its hierarchical microanostructure, which could buffer the volume change and shorten the diffusion length of Li~+ during the charge/discharge processes.