Single-ion conducting polymer electrolytes represent the ideal solution to reduce concentration polarization in lithium metal batteries (LMBs). This paper reports on the synthesis and characterization of single-ion ABA triblock copolymer electrolytes comprising PEO and poly(lithium 1-[3-(methacryloyloxy) propylsulfony1]-1-(trifluoromethylsulfonyl)imide) blocks, poly(LiMTFSI). Block copolymers are prepared by reversible addition -fragmentation chain transfer polymerization, showing low glass transition temperature (-55 to 7 degrees C) and degree of crystallinity (51-0%). Comparatively high values of ionic conductivity are obtained (up to approximate to 10(-4) S cm(-1) at 70 degrees C), combined with a lithium-ion transference number close to unity (t(Li+) approximate to 0.91) and a 4 V electrochemical stability window. In addition to these promising features, solid polymer electrolytes are successfully tested in lithium metal cells at 70 degrees C providing long lifetime up to 300 cycles, and stable charge/discharge cycling at C/2 (approximate to 100 mAh g(-1)). (C) 2017 Elsevier B.V. All rights reserved.