TY  - JOUR
AU  - Klein, Sven
AU  - Harte, Patrick
AU  - Henschel, Jonas
AU  - Bärmann, Peer
AU  - Borzutzki, Kristina
AU  - Beuse, Thomas
AU  - Wickeren, Stefan
AU  - Heidrich, Bastian
AU  - Kasnatscheew, Johannes
AU  - Nowak, Sascha
AU  - Winter, Martin
AU  - Placke, Tobias
TI  - On the Beneficial Impact of Li 2 CO 3 as Electrolyte Additive in NCM523 ∥ Graphite Lithium Ion Cells Under High‐Voltage Conditions
JO  - Advanced energy materials
VL  - 11
IS  - 10
SN  - 1614-6840
CY  - Weinheim
PB  - Wiley-VCH
M1  - FZJ-2021-02132
SP  - 2003756 -
PY  - 2021
AB  - Lithium ion battery cells operating at high‐voltage typically suffer from severe capacity fading, known as ‘rollover’ failure. Here, the beneficial impact of Li2CO3 as an electrolyte additive for state‐of‐the‐art carbonate‐based electrolytes, which significantly improves the cycling performance of NCM523 ∥ graphite full‐cells operated at 4.5 V is elucidated. LIB cells using the electrolyte stored at 20 °C (with or without Li2CO3 additive) suffer from severe capacity decay due to parasitic transition metal (TM) dissolution/deposition and subsequent Li metal dendrite growth on graphite. In contrast, NCM523 ∥ graphite cells using the Li2CO3‐containing electrolyte stored at 40 °C display significantly improved capacity retention. The underlying mechanism is successfully elucidated: The rollover failure is inhibited, as Li2CO3 reacts with LiPF6 at 40 °C to in situ form lithium difluorophosphate, and its decomposition products in turn act as ‘scavenging’ agents for TMs (Ni and Co), thus preventing TM deposition and Li metal formation on graphite.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000611080200001
DO  - DOI:10.1002/aenm.202003756
UR  - https://juser.fz-juelich.de/record/892524
ER  -