Acrylonitrile-grafted poly(vinyl alcohol) copolymer with a branched structure is synthesized and used as binder for a LiNi1/2Mn3/2O4 composite electrode. Electrode performances of composite electrodes with different binders are compared in Li cells at 50 degrees C. The branched copolymer has better coatability to active materials in comparison to a simple mixture of linear polymers and conventional PVdF as evidenced by hard X-ray photoelectron spectroscopy. Cyclability is effectively improved by using the branched copolymer at elevated temperatures because of high chemical stability of the coated polymer layer and formation of a protective layer on cycles. Moreover, excellent rate-capability is realized by applying the branched copolymer with high adhesive strength, and the composite electrode delivers 70 mAh g(-1) of discharge capacity at a rate of 1280 mA g(-1). (C) 2017 Elsevier B.V. All rights reserved.