Silicon is an attractive anode material due to its high theoretical capacity; however, microsilicon (mu Si) powders undergo large volume changes, repeated SEI damage, and particle debonding, leading to capacity-degrading transport losses. Here, we develop a water-borne polyurethane (WPU) ionomer binder composed of PTMEG/PEG soft segments and a PEG-citric-acid polyol. Partial LiOH neutralization converts carboxylic acids to lithium carboxylates, providing multipoint anchoring to Si/SiOx, reversible ionic associations, and Li-ion conduction pathways. Two formulations differing in PTMEG:di-PEG-CA ratio were synthesized via a solvent-minimized water-inversion route. NMR, HSQC, and FTIR confirm the targeted segmented ionomer architecture. The ionomeric WPUs are elastomeric (>1500% strain) with tunable modulus across formulations. Relative to a poly(acrylic acid) (PAA) binder, the ionic conductivity increases by an order of magnitude (1.8-2.2 & times; 10(-4) vs 2.4 & times; 10(-5) S cm(-1)), and the peel strength approximately doubles (similar to 2.0-2.2 vs similar to 0.9-1.0 N cm(-1)). In mu Si half-cells at 0.2 C, the capacity stabilizes at similar to 2.1-2.3 Ah g(-1) after 500 cycles with a Coulombic efficiency >= 99.98%, whereas PAA shows rapid fading to similar to 1.0 Ah g(-1). Postcycling Warburg slopes (19.3, 28.9 vs 123.2 Omega & centerdot;s(1)/(2)) and GITT-derived diffusion coefficients confirm substantially faster Li+ transport for both ionomeric binders. These results establish LiOH-neutralized WPU ionomers as a practical, NMP-free binder platform for mu Si anodes, with the degree of neutralization and soft/hard-segment ratio serving as key tuning parameters.