Which standard must Li-ion battery fulfil for CE marking in late 2020, IEC 62133:2012 or IEC 62133-2:2017?
I am no specialist for batteries, but after a quick query at DIN
at least I would consider these 4

IEC 61959:2004
IEC 61960-3:2017
IEC 62133-2:2017
IEC 21A/690/CD:2018

EDIT: IEC standards only apply if they are 1:1 equal to EN standards. CE is European, so the EN standards apply.
https://www.cen.eu/Pages/default.aspx
https://www.cenelec.eu/