Particles caulked by built-in high stiffness frame with fast ion transport capability: A two-pronged approach to solve chemo-mechanical failure for high-performance Ni-rich cathode materials

Nickel-rich cathode among the state-of-the-art cathode materials for lithium-ion batteries suffers from serious capacity decay ascribed to parasitic cathode-electrolyte reactions, which is associated with its chemo-mechanical instability including lattice distortion and particle disconnections. To solve this critical stress concentration-transmission related failure, herein the high stiffness Li2SiO3 with fast ion transport capability is caulked into grain boundaries of LiNi0.8Co0.1Mn0.1O2 secondary particles to build a holistic frame with two-pronged function: The caulked Li+-conductive fillings could not only mitigate the interfacial degradation and accelerate lithium ion diffusion, but more importantly, within the high Young's modulus Li2SiO3 frame, local stress accumulation during electrochemical cycling could be effectively dissipated to enable stress field homogenization, thus relieving stress accumulation and reinforcing particle integrity. Consequently, the engineered cathode exhibits superior cycling stability with negligible capacity fading after 100 cycles under 1C. The impressively improved cycling and rate performance originate from the suppression of microcrack and of interfacial side reactions on grain boundaries. We demonstrate that the idea of caulking high stiffness frame to rapidly dissipate stress could provide smart solutions for similar chemo-mechanically susceptible electrode materials towards building more advanced high energy batteries.