To mitigate the effects of climate change caused by greenhouse gas (GHG) emissions we need to move away from the combustion of fossil fuels for energy production. Thus, developing renewable energy conversion and storage technologies (water electrolyzers, hydrogen fuel cells, and redox flow batteries (RFBs)) will be crucial to reducing our GHG emissions. Pairing electrolyzers and fuel cells is an excellent alternative to the combustion of fossil fuels for both electricity production and the transportation sectors. Current commercially available fuel cells and electrolyzers are based on acidic proton exchange membrane (PEM) systems that require the use of expensive platinum-group metal (PGM) electrocatalysts. The alkaline analog, anion exchange membrane (AEM) systems can allow for the use of cheaper non-PGM electrocatalysts, but the stability and performance of the AEMs still need improvement to become commercially viable. Herein we synthesized polyethylene-based AEMs via ring-opening metathesis polymerization (ROMP) of cation functionalized monomers followed by hydrogenation. We tuned the properties of the AEMs to fit the needs of each device, with lower ion exchange capacity (IEC) for RFBs and higher IEC and different cationic moieties for the fuel cell applications. RFBs are a promising solution to grid-scale energy storage that utilize solvated redox-active species to store charge. However, solubilizing the charge storage species allows for their crossover through the separating membrane, causing electrolyte mixing and leads to capacity fade and battery failure. In Chapter 2, we synthesized a series of trimethylammonium-functionalized polyethylene AEMs with varied IECs and employed them in RFB cells to assess the influence of IEC on electrolyte crossover. We observed a direct relationship where decreasing the IEC reduced the electrolyte crossover. Additionally, we identified an AEM that exhibits limited electrolyte crossover and stable cycling over 1000 charge/discharge cycles. In Chapter 3, we synthesized a series of 17 polyethylene-based AEMs with different quaternary ammonium-functionalities. The initial conductivity and conductivity stability was determined for each AEM to elucidate the relationship between cation and stability once the cation has been incorporated into a polymer. We found that the piperidinium-functionalized AEM resulted in the highest stability under alkaline conditions. Due to its promising stability, it was chosen for further analysis in a fuel cell membrane electrode assembly (MEA) and it was found that increasing the IEC improved the MEA performance.