Recent Challenges and Optimization Strategies of Thick Electrodes in High-Energy-Density Batteries

With the continuous development of industries such as electric vehicles and renewable energy storage systems, societal demands on battery performance are steadily increasing, particularly regarding their capacity limit and stability. Thick electrodes have gained significant attention due to their capability to substantially enhance the areal energy density of electrodes, thereby improving the overall energy storage capacity of the full cell. However, the practical applications encounter challenges of sluggish ion transport, severe polarization, and insufficient mechanical stability. These bottlenecks significantly restrict the performance of batteries employing thick electrodes. This paper systematically reviews the major challenges of thick electrodes, analyzing the underlying causes of these issues from electrochemical and mechanical perspectives. Additionally, current optimization strategies are summarized, including approaches such as reducing tortuosity, adjusting pore structure, regulating thermodynamic parameters, innovating electrode fabrication processes, and suppressing crack formation. These strategies aim to balance high energy density, enhanced performance improvement, and structural integrity, while promoting the large-scale production of thick electrodes. Looking forward, with continued improvements based on the five strategic directions outlined in this review, next-generation large-scale manufactured thick electrodes are expected to enhance battery storage capabilities while maintaining excellent electrochemical performance and mechanical robustness, injecting new vitality into the battery market.