From some quick digging, seems like the '11 and '12 Leaf had the EM61 motor (e.g. https://techcrunch.com/2010/11/02/nissan-releases-final-specs-on-the-leaf/ and https://www.marklines.com/en/report_all/rep1049_201202).
AFAIK, EM57 was used from '13 to '17 and even '18 (e.g. https://www.autoblog.com/2012/11/20/2013-nissan-leaf-details-japan-more-range-better-charger/, lots of Google search results, and http://nissannews.com/en-US/nissan/usa/releases/overview-2018-nissan-leaf).
Presumably all of these are re: changes from EM61 to EM57:
https://web.archive.org/web/20170714101025/http://articles.sae.org/11993/
http://saegtl.org/ev/data/uploads/ev-content/gtlev_tp_2014-01-1879.pdf
https://web.archive.org/web/20130814161311/https://www.nissan-global.com/EN/TECHNOLOGY/OVERVIEW/e_powertrain.html