Growth of Hierarchical MnO2 Nanospike on Three-Dimensional Carbon Network for Enhancing Rechargeability as High-rate Alkaline Battery Cathode

摘要

MnO2 material has been widely utilized in primary batteries because of its high theoretical capacity,rich resources,and low cost,which,however,does not exhibit satisfactory reversible capacity and cycle life when used as a secondary battery cathode.To upgrade the rechargeability of MnO2 material,we herein fabricated a hierarchical nanocomposite by in-situ growth of MnO2 nanostructure on carbonized melamine sponge(MnO2/C).The optimized MnO2/C nanostructure consisting of hierarchical nanospikes shows a high reversible capacity of 205 mAh·g~(-1)at 1 C and retained 96% of its initial capacity after 400 cycles,and even at 5 C(i.e.1540 mA?g-1),the capacity retention still reaches 90% after 400 cycles,indicative of its remarkable high-rate cycling stability.This study provides a new avenue for designing high-rate rechargeable MnO2 cathode and may further advance the development of MnO2-based secondary batteries.