1] Carbon Research Laboratory, Liaoning Key Lab for Energy Materials and Chemical Engineering, State Key Lab of Fine Chemicals, Dalian University of Technology, Dalian 116024, China [2] School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459, Singapore.
Carbon Research Laboratory, Liaoning Key Lab for Energy Materials and Chemical Engineering, State Key Lab of Fine Chemicals, Dalian University of Technology, Dalian 116024, China.
Nat Commun. 2014 Sep 25;5:5002. doi: 10.1038/ncomms6002.
Lithium-sulphur batteries are one very appealing power source with high energy density. But their practical use is still hindered by several issues including short lifespan, low efficiency and safety concern from the lithium anode. Polysulphide dissolution and insulating nature of sulphur are generally considered responsible for the capacity degradation. However, the detachment of discharge products, that is, highly polar lithium sulphides, from nonpolar carbon matrix (for example, graphene) has been rarely studied as one critical factor. Here we report the strongly covalent stabilization of sulphur and its discharge products on amino-functionalized reduced graphene oxide that enables stable capacity retention of 80% for 350 cycles with high capacities and excellent high-rate response up to 4 C. The present study demonstrates a feasible and effective strategy to solve the long-term cycling difficulty for lithium-sulphur batteries and also helps to understand the capacity decay mechanism involved.
锂硫电池是一种极具吸引力的高能量密度电源。但它们的实际应用仍受到多种问题的阻碍，包括短寿命、低效率以及对锂阳极的安全担忧。多硫化物的溶解和硫的绝缘性质通常被认为是导致容量衰减的原因。然而，放电产物，即高极性的硫化锂，从非极性碳基质（例如石墨烯）上的脱离，作为一个关键因素，很少被研究过。在这里，我们报告了在氨基功能化的还原氧化石墨烯上对硫及其放电产物的强共价稳定，这使得电池在 350 个循环中具有 80%的稳定容量保持率、高容量和出色的高倍率响应能力，高达 4C。本研究为解决锂硫电池的长期循环难题提供了一种可行且有效的策略，也有助于理解所涉及的容量衰减机制。
