Mechanically reinforced Ni-rich cathodes for High-Power and Long-Life All-Solid-State batteries.

• A scalable microstructure engineering strategy for developing mechanically reinforced Ni-rich cathodes. • A well-designed polycrystalline Ni-rich cathode consisting of densely packed large-size primary particles. • Superior rate performance (31.7 mAh g−1 at 4C) and cyclic stability (84.1% after 100 cycles at 0.2C). Mechanical integrity is crucial for the intra-particle ionic/electronic transfer in all-solid-state batteries. However, electrode particles suffer severe electrochemo-mechanical degradations during electrode compaction and high-voltage operation, which is extremely true in the popular high-energy cathodes of fragile polycrystalline Ni-rich oxides composed of loosely stacked nanoparticles. Herein, we develop mechanically reinforced polycrystalline Ni-rich cathodes consisting of densely packed large-size primary particles based on a scalable microstructure engineering strategy. The structural characterization and finite element simulation results demonstrate that this well-designed microstructure of cathodes can suppress the stress/strain accumulation and formation of cracks, and thus maintain the original microstructure and highly percolated ionic/electronic networks. All-solid-state batteries based on mechanically reinforced Ni-rich cathodes achieve significantly improved specific capacity, rate capability, and cyclic stability. This work provides a new sight for designing advanced cathodes to boost the development of high-power and long-life all-solid-state batteries. [ABSTRACT FROM AUTHOR]