Enhanced thermal safety and rate capability of nickel-rich cathodes via optimal Nb-doping strategy

• Published in: Electrochimica acta Vol. 487; p. 144216
• Main Authors: Gu, Hao, Mu, Yue, Zhang, Songtong, Li, Yongqi, Hu, Hailiang, Zhu, Xiayu, Meng, Wenjie, Qiu, Jingyi, Ming, Hai
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 20.05.2024
• Subjects: Cycle stability; Nickel-rich cathode materials; Niobium doping; Rate capability; Thermal safety; Cycle stability; Niobium doping; Nickel-rich cathode materials; Thermal safety; Rate capability
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2024.144216

•A series of Nb-doping products are successfully prepared by solid phase strategy.•The suitable mole ratio of Nb-doping in LiNi0.8Co0.1Mn0.1O2 is identified to 0.1 %.•Lower Nb-doping benefits to higher capacity, the higher endows good rate capability.•The Nb-doping is conducive to high structural stability and electron conductivity.•The Nb-doping Ni-rich cathode delivers a more stable thermal safety. Nickel-rich layered oxides have garnered great attention as promising cathode materials in lithium-ion batteries for their high specific capacity, rate capability and comparatively lower cost. However, the long cycling with a high current scenario is still a critical challenge, resulting from the lattice cracks and high temperature which are induced by rapid Li-ions intercalation/extraction and local heat accumulation under component voltage. Besides the deterioration of electrochemical performance, these limitations further lead to the impairment of structure or even thermal runaway for nickel-rich layered oxides. Herein, considering the superiorities of niobium element with multilevel electron orbitals and suitable atomic radius, a strategy of nickel-rich material modified by niobium-doping is proposed. The incorporated niobium forms a strong niobium-oxygen bonding, which promotes structure stability, ions diffusivity, and electron conductivity of nickel-rich cathode (LiNi0.8Co0.1Mn0.1O2). Accordingly, the niobium-doping cathode deliver the specific capacities of 166.4 mAh g−1 and 151.02 mAh g−1 after 100 cycles at 1 C and 5 C (1C = 200 mAh g−1), especially with the capacity retention of 88.90 % and 89.06 %. Moreover, the niobium-doping cathode exhibit a more stable thermal safety with a reversibility around 76.75 % after 100 cycles at 1 C under 50 ℃, whereas is only 36.03 % for blank sample. Accompanied with exploring the stabilization for crystalline structure and superficial electronic structure, a generic approach to synthesize excellent Ni-rich cathode materials is identified, accelerating their endurance application in complicated scenes, particularly at high-temperature and high-rate operation conditions. A series of Nb-doping products are successfully prepared by solid phase strategy, in which the suitable mole ratio of Nb-doping in LiNi0.8Co0.1Mn0.1O2 is identified to around 0.1 %; The lower content of Nb-doping benefits to higher capacity, conversely, the higher endows better rate capability; As expatiated, this shows that the Nb-doping is conducive to high structural stability and electron conductivity, especially, the Nb-doping Ni-rich cathode delivers a more stable thermal safety. [Display omitted]