Single crystalline cathode of NaCl-assisted NMC532 for enhancing lithium-ion battery performance

ABSTRACT Single crystal cathode materials are attractive because they offer a long cycle life and good temperature stability. The addition of salt during cathode material synthesis is performed to improve the structure, helping to form a single crystal material. This study investigates the effect of NaCl addition on the crystal structure, morphology, and electrochemical performance of the LiNi 0 . 5 Mn 0 . 3 Co 0 . 2 O 2 (NMC532) single crystal cathode material. NMC532 precursor material was synthesized via a coprecipitation process, followed by high temperature calcination with varying NaCl content (0%, 4%, 8%, and 12% by weight). XRD analysis revealed the formation of a well-developed, ordered hexagonal layered crystal structure. SEM analysis showed that NaCl-assisted NMC532 cathode produced a single crystal morphology with more uniform particle sizes, which increased with rising salt content. In terms of electrochemical performance, NaCl-4% sample revealed improved redox reversibility and better anodic/cathodic peaks in CV testing, along with a decrease in charge transfer resistance (R ct ) in EIS testing. Furthermore, the results of battery specific capacity, rate capability, and cycle life testing also indicate that the NaCl-4% battery delivers the best performance among the other samples. This indicates that NaCl-assisted material with proper composition not only facilitates single crystal growth but also improves the interfacial stability and overall electrochemical performance.