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SUMMARY:Li-ion and Li-air battery electrochemistry: harnessing oxygen redo
 x and understanding interfacial reactivity in high energy batteries
DTSTART:20190205T150000
DTEND:20190205T160000
DTSTAMP:20260427T215245Z
UID:5c5e69e160a643e71163d1bd316731106655ca7ca72223acc94311db
CATEGORIES:Conferences - Seminars
DESCRIPTION:Prof. Bryan McCloskey\nUniversity of California\nMultiple dire
 ctions in battery research are now being pursued with the goal of advancin
 g beyond the specific energy limits imposed by current Li-ion batteries. 
  When considering the design of new high-energy storage systems\, new mate
 rials\, processes\, or chemistries are introduced that are inherently more
  unstable than conventional Li-ion battery materials\, resulting in limite
 d battery cycle life and safety. Two such examples of high energy battery
  chemistries\, high voltage operation of Ni-rich Li[Ni\, Mn\, Co]O2Li+inse
 rtion electrodes (Ni-rich NMC) and Li-O2electrochemistry\, will be discuss
 ed in this presentation.Previous observations of high-voltage instabilitie
 s include NMC surface reconstruction\, transition metal dissolution\, elec
 trolyte decomposition\, and formation of solid surface species. However\, 
 the picture of these processes is still incomplete\, with the dependence o
 n electrolyte and NMC composition not yet fully understood.  I will pres
 ent results in which isotopic labeling of 18O in Ni-rich NMCs is combined
  with quantitative gas evolution analysis to identify key contributions to
  these high voltage instabilities\, including instabilities related to sol
 id-state anionic (oxygen) redox and the surprising impact of residual soli
 d lithium carbonate (Li2CO3) on electrolyte and electrode degradation. The
 se results are reminiscent of similar issues with Li2CO3formation during L
 i-O2battery operation\, where large overpotentials are observed during bat
 tery charging as a result of parasitic interfacial carbonate formation. 
  This presentation will emphasize the need to accurately quantify these m
 inor parasitic side reactions to fully understand their large influence on
  battery performance.  
LOCATION:BCH 2201 https://plan.epfl.ch/?room==BCH%202201
STATUS:CONFIRMED
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