Reversible planar gliding and microcracking in a single-crystalline Ni-rich cathode

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• High-energy nickel (Ni)-rich cathodes are crucial for advanced lithium (Li)-ion batteries.
• These cathodes face challenges like moisture sensitivity, side reactions, and gas generation.
• Single-crystalline Ni-rich cathodes offer potential solutions by minimizing phase boundaries and material surfaces.

Purpose of the Study:

• To investigate the fundamental linkage between overpotential, microstructure, and electrochemical behaviors in single-crystalline Ni-rich cathodes.
• To understand the mechanisms behind particle fracture in these advanced battery materials.
• To identify strategies for mitigating synthesis-related defects.

Main Methods:

• Synthesis of high-performance single-crystalline Ni-rich cathodes.
• Microscopic analysis to observe microstructural changes.
• Electrochemical testing to correlate performance with structural integrity.

Main Results:

• Observed reversible planar gliding and microcracking along the (003) plane in single-crystalline Ni-rich cathodes.
• Correlated the formation of microstructure defects with localized stresses induced by Li-ion concentration gradients.
• Demonstrated a link between lattice defects and electrochemical performance.

Conclusions:

• The reversible formation of microstructural defects is a key factor in the performance of single-crystalline Ni-rich cathodes.
• Understanding Li-ion concentration gradients and induced stresses is crucial for preventing particle fracture.
• This research provides foundational knowledge for designing more robust and high-performance single-crystalline Ni-rich cathodes for next-generation lithium-ion batteries.