Waxberry-like nanosphere Li4Mn5O12 as high performance electrode materials for supercapacitors

Abstract

Porous materials have superior electrochemical performance owing to its their structure, which could increase the specific and contact area with the electrode. The spinel Li4 Mn5 O12 has a three-dimensional tunnel structure for a better diffusion path, which has the advantage of lithium ion insertion and extraction in the framework. However, multi-space spherical materials with single morphologies are rarely studied. In this work, waxberry-like and raspberry-like nanospheres for Li4 Mn5 O12 have been fabricated by the wet chemistry and solid-state methods for the first time. The diameter of a single waxberry-and raspberry-like nanosphere is about 1 µm and 600 nm, respectively. The specific capacitance of Li4 Mn5 O12 was 535 mF cm−2 and 147.25 F g−1 at the scan rate of 2 mV s−1, and the energy density was 110.7 Wh kg−1, remaining at 70% after 5000th charge-discharge cycles. Compared with raspberry-like nanosphere Li4 Mn5 O12, the waxberry-like nanoporous spinel Li4 Mn5 O12 shows the better electrochemical performance and stability; furthermore, these electrochemical performances have been improved greatly compared to the previous studies. All these results indicate that the waxberry-like nanoporous spinel Li4 Mn5 O12 could provide a potential application in high performance supercapacitors.