High-nickel cathode materials are one of the most promising candidates for lithium-ion batteries with superior comprehensive performance. These materials can achieve higher energy density than conventional lithium cobalt oxide, and have lower cost and high environmental benignity. To reduce the cost further to meet the growing energy demand, the development of cobalt-free high-nickel cathode materials becomes one of research challengess. This review discussed the feasibility of cobalt removal and the key challenges for cobalt-free high-nickel cathodes. The modification strategies were summarized based on recent related studies. In addition, the future research direction of cobalt-free high-nickel cathodes was also proposed.