Realizing ultrahigh-voltage performance of single-crystalline LiNi0.55Co0.15Mn0.3O2 cathode materials by simultaneous Zr-doping and B2O3-coating

• Published in: Journal of alloys and compounds Vol. 903; p. 163999
• Main Authors: Shen, Jixue, Deng, Duo, Li, Xiao, Zhang, Bao, Xiao, Zhiming, Hu, Changqing, Yan, Xiaozhi, Ou, Xing
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.05.2022; Elsevier BV
• Subjects: B2O3 coating; Boron oxides; Cathodes; Coating; Crystal structure; Crystallinity; Cycles; Discharge; Doping; Electrode materials; Flux density; High voltages; Lithium; Lithium-ion batteries; Rechargeable batteries; Retention; Single crystals; Single-crystalline NCM; Synergistic effect; Transition metals; Voltage stability; Zirconium; Zr doping; Lithium-ion batteries; Synergistic effect; Zr doping; Single-crystalline NCM; B2O3 coating
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2022.163999

Improving the high-voltage stability of cathode materials is a new strategy to enhance the energy density of lithium-ion batteries (LIBs) in recent years. However, as a traditional cathode material, the low reversible capacity at high cut-off voltages (≥ 4.3 V) greatly restricts the application of LiCoO2. Herein, we have rationally synthesized a novel single-crystalline LiNi0.55Co0.15Mn0.3O2 cathode material (Z-NCM@B) by using the synergistic effect of Zr-doping and B2O3-coating. Excitedly, the modified Z-NCM@B cathode material shows improved high-voltage stability and excellent long-term cycling performance. Furthermore, it is revealed that the stronger ZrO bond formed by Zr4+ dopant can stabilize the crystal structure and promote the migration of Li+ in the cathode materials. Meanwhile, the uniform B2O3 coating layer effectively suppresses the material corrosion by electrolyte and reduces the loss of transition metal ions during the charge/discharge cycle process. As anticipated, the Z2-NCM@B2 || graphite pouch-type full cell exhibits an advanced capacity retention of 96.9% over 250 cycles at an operating voltage of 4.2 V, while the capacity retention of the pristine NCM is only 88%. Besides, the Z2-NCM@B2 coin-cell retains a discharge capacity of 145.2 mA h g−1 at 1 C with a satisfactory capacity retention of 79.2% after 100 cycles within a broad voltage range between 2.95 and 4.7 V, which is much superior than that for the pristine NCM (130.9 mA h g−1, 70.9%). This synergistic modification strategy offers a reference for the practical application of NCM cathode materials with high-voltage stability and long-term cycling performance in LIBs. The single-crystalline LiNi0.55Co0.15Mn0.3O2 (SC-NCM) with a synergistic modification strategy is developed, which demonstrates remarkable cycling stability with satisfied reversible capacity at harsh conditions, achieving higher energy density and ultralong cyclic life. Furthermore, the fundamental understandings of synergistic modification strategy on the material structure and phase transformation are clearly unraveled, paving a new avenue to promote the high-voltage performance of commercial single-crystal NCM cathode. [Display omitted] •Synergistic modification strategy is explored for single-crystalline NCM cathode.•Zr-doping and B2O3-coating modification are adopted to modify the NCM cathode.•It exhibits significantly improved high-voltage performance and long-term cycle performance.•This work provides an insight into the modification of single-crystalline NCM cathode.