A High-Nickel Cathode Material for Lithium-Ion Batteries Integrating a Proposed 3D Ionic Percolation Network and Interwoven Layered/Rock-Salt Nanodomains

High-nickel single-crystal cathodes effectively address the poor mechanical stability and severe side reactions that plague their polycrystalline counterparts. However, they introduce new structural challenges, including extended Li+ diffusion pathways, which in turn lead to structural slips, lattice distortions, and phase transformations, ultimately compromising both electrochemical capacity and structural stability. Herein, we report a state-of-the-art cathode architecture for high-nickel materials, derived from high-energy neutron irradiation of single-crystal LiNi0.92Co0.06Mn0.02O2 particles. This process induces long-range Li/Ni antisite disorder and short-range metal-oxygen octahedral distortions, concurrently yielding a nanostructure of abundant grain boundaries and interwoven layered/rock-salt nanodomains within the single-crystalline particles. These grain boundaries are proposed to constitute a 3D percolation network for rapid Li+ transport, whereas the interwoven nanodomains may act as local structural reinforcing units that help suppress irreversible phase transitions and the propagation of interfacial side reactions during cycling. These characteristics are favorable for sustaining continuous Li+ deintercalation/intercalation and reversible electrochemistry, thereby preserving the structural stability of the single-crystal framework while simultaneously shortening diffusion pathways. As a result, the engineered cathode delivers a high specific discharge capacity of 213.9 mAh/g at 0.2 C and 152.2 mAh/g at 10 C (within 4.5 V). Moreover, it retains 80.0% of its initial capacity after 450 cycles at 5 C, significantly outperforming the reference single-crystal cathode (64.2%). This work establishes high-energy neutron irradiation as an effective cathode reconstruction strategy, offering a viable route toward robust, high-energy cathodes.