Ni-rich cathode materials with concentration gradients for high-energy and safe lithium-ion batteries: A comprehensive review | 2025 Publication type A2 Review article, literature review, systematic review Author(s) Yerkinbekova Yerkezhan, Kumarov Alisher, Tatykayev Batukhan, Mentbayeva Almagul, Repo Eveliina, Laakso Ekaterina Other Focus Area LUT School of Engineering Sciences