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In-Situ Synthesis of N,O, P-Doped Hierarchical Porous Carbon from Poly-bis(phenoxy)phosphazene for Polysulfide-Trapping Interlayer in Lithium-Sulfur Batteries |
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| Authors: | Munan Qiu Dr Xuewei Fu Fan Yang Prof Shengli Qi Prof Zhanpeng Wu Prof Wei-Hong Zhong |
| Institution: | 1. School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164 USA
Key Laboratory of Carbon Fiber and Functional Polymers, Beijing University of Chemical Technology Ministry of Education, Beijing, 100029 P. R. China State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029 P. R. China;2. School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164 USA;3. Key Laboratory of Carbon Fiber and Functional Polymers, Beijing University of Chemical Technology Ministry of Education, Beijing, 100029 P. R. China State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029 P. R. China;4. Key Laboratory of Carbon Fiber and Functional Polymers, Beijing University of Chemical Technology Ministry of Education, Beijing, 100029 P. R. China |
| Abstract: | The shuttling of polysulfides is the most detrimental contribution to degrading the capacity and cycle stability of lithium-sulfur (Li−S) batteries. Adding a carbon interlayer to prevent the polysulfides from migrating is feasible, and a rational design of the structures and surface properties of the carbon layer is essential to increasing its effectiveness. Herein, we report a hierarchical porous carbon (HPC) created by carbonization of bis(phenoxy)phosphazene and in-situ doping of triple heteroatoms into the carbon lattice to fabricate an effective polysulfide-trapping interlayer. The generated carbon integrates the advantages of a hierarchical porous structure, a high specific area and rich dopants (N, O and P), to yield chemisorption and physical confinement for polysulfides and fast ion-transport synergistically. The HPC interlayer significantly improves the electrochemical performance of Li−S batteries, including an exceptional discharge capacity of 1509 mA h/g at 0.06 C and a high capacity retention of 83.7 % after 250 cycles at 0.3 C. This work thus proposes a facile in-situ synthesis of heteroatom-doped carbon with rational porous structures for suppressing the shuttle effect. |
| Keywords: | hierarchical porous carbon in-situ doping interlayers Li−S batteries shuttle effects |