Innovatively　designed,　modified,　and　synthesized　catalyst/electrode　materials　are　of　great　importance　in　improving　the　performance　of　electrochemical　energy　devices　for　energy　storage　and　conversion.　Among　various　material　modification　technologies,　the　ion-irradiation　technique　has　been　recognized　as　a　promising　technology,　which　can　effectively　modify　and　design　materials　through　controlling　the　key　irradiation　parameters,　such　as　irradiation　ion　species,　energy　and　fluence.　The　advantages　of　the　ion-irradiation　technique　are　high　precision,　favorable　controllability,　favorable　repeatability,　etc.;　meanwhile,　it　can　realize　arbitrary　element　doping　and　defect　control　for　many　catalyst/electrode　materials.　Notably,　it　does　not　induce　any　impurities　into　the　target　materials　during　the　ion-irradiation　process,　which　is　superior　to　many　chemical　modifications.　The　effects　of　ion-irradiation　on　catalyst/electrode　materials　in　recent　years　are　described　in　this　review,　including　defect　introduction,　regulation　of　the　electronic　structure,　morphology　control,　synthesis,　and　element　doping.　Then,　the　applications　of　ion　irradiated　catalyst/electrode　materials　in　water　electrolysis/photoelectrolysis　cells,　lithium-ion　batteries,　and　supercapacitors　are　systematically　summarized　with　an　emphasis　on　the　advantages　of　boosting　the　properties　of　materials.　Finally,　the　challenges　and　strategies　are　proposed　for　developing　more　practical　ion-irradiation　techniques　towards　high-performance　catalyst/electrode　materials.