NbSe2 meets C2N: a 2D-2D heterostructure catalysts as multifunctional polysulfide mediator in ultra-long-life lithium–sulfur batteries

The shuttle effect and sluggish conversion kinetics of lithium polysulfides (LiPS) hamper the practical application of lithium–sulfur batteries (LSBs). Toward overcoming these limitations, herein an in situ grown C2N@NbSe2 heterostructure is presented with remarkable specific surface area, as a Li–S...

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Detalles Bibliográficos
Autores: Yang, Dawei, Liang, Zhifu, Zhang, Chaoqi, Jacas Biendicho, Jordi|||0000-0001-5981-6168, Spadaro, Maria Chiara, Li, Mengyao, Moghaddam, Ahmad Ostovari, Llorca Piqué, Jordi|||0000-0002-7447-9582, Morante Lleonart, Joan Ramon|||0000-0002-4981-4633, Arbiol, Jordi, Cabot, Andreu
Tipo de recurso: artículo
Fecha de publicación:2021
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/359124
Acceso en línea:https://hdl.handle.net/2117/359124
https://dx.doi.org/10.1002/aenm.202101250
Access Level:acceso abierto
Palabra clave:Catalysis
Lithium-sulfur batteries
Catàlisi
Àrees temàtiques de la UPC::Enginyeria química
Descripción
Sumario:The shuttle effect and sluggish conversion kinetics of lithium polysulfides (LiPS) hamper the practical application of lithium–sulfur batteries (LSBs). Toward overcoming these limitations, herein an in situ grown C2N@NbSe2 heterostructure is presented with remarkable specific surface area, as a Li–S catalyst and LiPS absorber. Density functional theory (DFT) calculations and experimental results comprehensively demonstrate that C2N@NbSe2 is characterized by a suitable electronic structure and charge rearrangement that strongly accelerates the LiPS electrocatalytic conversion. In addition, heterostructured C2N@NbSe2 strongly interacts with LiPS species, confining them at the cathode. As a result, LSBs cathodes based on C2N@NbSe2/S exhibit a high initial capacity of 1545 mAh g-1 at 0.1 C. Even more excitingly, C2N@NbSe2/S cathodes are characterized by impressive cycling stability with only 0.012% capacity decay per cycle after 2000 cycles at 3 C. Even at a sulfur loading of 5.6 mg cm-2, a high areal capacity of 5.65 mAh cm-2 is delivered. These results demonstrate that C2N@NbSe2 heterostructures can act as multifunctional polysulfide mediators to chemically adsorb LiPS, accelerate Li-ion diffusion, chemically catalyze LiPS conversion, and lower the energy barrier for Li2S precipitation/decomposition, realizing the “adsorption-diffusion-conversion” of polysulfides.

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