화학공학소재연구정보센터
Applied Surface Science, Vol.497, 2019
MOFs-derived nitrogen-doped carbon interwoven with carbon nanotubes for high sulfur content lithium-sulfur batteries
Despite their high energy density, low-cost, and low environmental impacts compared with the current state-of-the-art lithium-ion batteries, lithium-sulfur (Li-S) batteries still suffer from the low sulfur content, dissolution of polysulfides and capacity loss, which hinder their commercial application. To address these issues, nitrogen-doped cubic carbon (NC) interwoven with carbon nanotubes (CNT) host is introduced to achieve high sulfur content for lithium-sulfur batteries. The NC/CNT composites are derived from metal-organic frameworks (MOFs), which can physically confine sulfur, thus providing efficient sulfur loading. The sulfur content in the as-obtained S@NC/CNT composite is as high as 89 wt%, while the cathode membrane has a sulfur loading of 3.6 mg cm(-2). In addition, the NC/CNT composite can obstruct the dissolution and outward diffusion of polysulfides. Impressively, under the high sulfur content and high sulfur loading conditions, the S@NC/CNT cell exhibits initial specific capacity of 1141 mA h g(-1) at the current rate of 0.5C (837.5 mA g(-1)) and the capacity retains 674.4 mA h g(-1) after 120 cycles. The S@ NC/CNT cathode also shows high areal capacity (4.1 mA h cm(-2)). The NC/CNT composite derived from MOFs has great potential applications for high-sulfur loading cathodes.