Tackling the Grand Challenges in Practical Ultrahigh-Loading (>10 mg cm⁻²) Lithium-Sulfur Batteries

The transition of lithium–sulfur (Li–S) batteries from laboratory research to commercial application necessitates the use of ultrahigh sulfur loadings (>10 mg cm⁻²). However, this requirement intensifies three fundamental challenges that are minor at low loadings but critical under practical conditions: (i) severely hindered ion and electron transport in thick electrodes, (ii) exacerbated polysulfide shuttling and sluggish conversion kinetics, and (iii) mechanical degradation due to large volume changes. This review systematically outlines these challenges and the corresponding strategies designed for the ultrahigh-loading regime. We focus on multidimensional solutions spanning from material design to system-level engineering: building efficient transport pathways through structural design to facilitate ion and electron conduction; enhancing catalytic conversion and suppressing the shuttle effect via interface and electrolyte engineering; and preserving electrode integrity through robust architectures and functional binders. The discussion throughout is centered on practical viability, assessing the scalability and industrial compatibility of the proposed strategies. Additionally, we provide perspectives on future research directions, highlighting the importance of integrated multifunctional designs, the adoption of practical full-cell evaluation under lean-electrolyte conditions, and the pursuit of next-generation systems such as solid-state Li–S batteries. This review aims to bridge the gap between fundamental research and industrial requirements, offering a roadmap for developing high-energy-density, long-cycle-life Li–S batteries that meet the demands of real-world applications.