A Surface Se-Substituted LiCo[O2- δ Seδ ] Cathode with Ultrastable High-Voltage Cycling in Pouch Full-Cells.
Adv Mater
; 32(50): e2005182, 2020 Dec.
Article
en En
| MEDLINE
| ID: mdl-33174311
ABSTRACT
Cycling LiCoO2 to above 4.5 V for higher capacity is enticing; however, hybrid O anion- and Co cation-redox (HACR) at high voltages facilitates intrinsic Oα - (α < 2) migration, causing oxygen loss, phase collapse, and electrolyte decomposition that severely degrade the battery cyclability. Hereby, commercial LiCoO2 particles are operando treated with selenium, a well-known anti-aging element to capture oxygen-radicals in the human body, showing an "anti-aging" effect in high-voltage battery cycling and successfully stopping the escape of oxygen from LiCoO2 even when the cathode is cycled to 4.62 V. Ab initio calculation and soft X-ray absorption spectroscopy analysis suggest that during deep charging, the precoated Se will initially substitute some mobile Oα - at the charged LiCoO2 surface, transplanting the pumped charges from Oα - and reducing it back to O2- to stabilize the oxygen lattice in prolonged cycling. As a result, the material retains 80% and 77% of its capacity after 450 and 550 cycles under 100 mA g-1 in 4.57 V pouch full-cells matched with a graphite anode and an ultralean electrolyte (2 g Ah-1 ).
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Banco de datos:
MEDLINE
Idioma:
En
Revista:
Adv Mater
Asunto de la revista:
BIOFISICA
/
QUIMICA
Año:
2020
Tipo del documento:
Article
País de afiliación:
Estados Unidos