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Trapped O2 and the origin of voltage fade in layered Li-rich cathodes.
Marie, John-Joseph; House, Robert A; Rees, Gregory J; Robertson, Alex W; Jenkins, Max; Chen, Jun; Agrestini, Stefano; Garcia-Fernandez, Mirian; Zhou, Ke-Jin; Bruce, Peter G.
Afiliación
  • Marie JJ; Department of Materials, University of Oxford, Oxford, UK.
  • House RA; The Faraday Institution, Didcot, UK.
  • Rees GJ; Department of Materials, University of Oxford, Oxford, UK. robert.house@materials.ox.ac.uk.
  • Robertson AW; The Faraday Institution, Didcot, UK. robert.house@materials.ox.ac.uk.
  • Jenkins M; Department of Materials, University of Oxford, Oxford, UK.
  • Chen J; The Faraday Institution, Didcot, UK.
  • Agrestini S; Department of Materials, University of Oxford, Oxford, UK.
  • Garcia-Fernandez M; Department of Materials, University of Oxford, Oxford, UK.
  • Zhou KJ; Department of Materials, University of Oxford, Oxford, UK.
  • Bruce PG; Diamond Light Source, Didcot, UK.
Nat Mater ; 23(6): 818-825, 2024 Jun.
Article en En | MEDLINE | ID: mdl-38429520
ABSTRACT
Oxygen redox cathodes, such as Li1.2Ni0.13Co0.13Mn0.54O2, deliver higher energy densities than those based on transition metal redox alone. However, they commonly exhibit voltage fade, a gradually diminishing discharge voltage on extended cycling. Recent research has shown that, on the first charge, oxidation of O2- ions forms O2 molecules trapped in nano-sized voids within the structure, which can be fully reduced to O2- on the subsequent discharge. Here we show that the loss of O-redox capacity on cycling and therefore voltage fade arises from a combination of a reduction in the reversibility of the O2-/O2 redox process and O2 loss. The closed voids that trap O2 grow on cycling, rendering more of the trapped O2 electrochemically inactive. The size and density of voids leads to cracking of the particles and open voids at the surfaces, releasing O2. Our findings implicate the thermodynamic driving force to form O2 as the root cause of transition metal migration, void formation and consequently voltage fade in Li-rich cathodes.
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Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Idioma: En Revista: Nat Mater Asunto de la revista: CIENCIA / QUIMICA Año: 2024 Tipo del documento: Article País de afiliación: Reino Unido Pais de publicación: Reino Unido
Texto completo
Añadir a Mi BVS
Imprimir
XML
PubMed Links
Buscar en Google

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Idioma: En Revista: Nat Mater Asunto de la revista: CIENCIA / QUIMICA Año: 2024 Tipo del documento: Article País de afiliación: Reino Unido Pais de publicación: Reino Unido