Details

Autor(en) / Beteiligte

• Li, Lina
• Han, Enshan
• Zhu, Lingzhi
• Qiao, Shunpan
• Du, Chenyu
• Liu, Hui

Titel

Effect of Zr doping and Al-Zr co-doping on LiNi0.5Co0.25Mn0.25O2 for lithium-ion batteries

Ist Teil von

• Solid state ionics, 2020-03, Vol.346, p.115220, Article 115220

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2020

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Cathode material Li(Ni0.5Co0.25Mn0.25)1-xZrxO2 (x = 0, 0.005, 0.01, 0.02, 0.03) and Li(Ni0.5Co0.25-yMn0.25Aly)0.99Zr0.01O2 (y = 0, 0.01, 0.02, 0.03) were synthesized by coprecipitation method. The structure and electrochemical properties of cathode materials were mainly studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), charge/discharge test, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results of XRD show that Zr doping and Al-Zr co-doping cannot destroy the crystal structure, and they are all beneficial to structural stability. Electrochemical results show that the appropriate amount of Zr4+ doping can improve the rate and cycle performance. However, there is no further increase in the rate performance and cycle stability when Co is replaced with Al. Because of the 3a site occupation of the doped ions, it is possible that the diffusion of lithium ions is hindered. And Al is low electrochemically inert. In particular, x = 0.01 exhibited the best rate performance and cycle stability in all samples. The specific discharge capacity of the material is 151.0 mAh/g at 1C, and it still up to 173.3 mAh/g at 0.1C after experiencing high-rate discharge. And the capacity retention rate is 87.53% at 0.1C after 45 cycles. When Al3+ and Zr4+ are co-doped, the performance of y = 0.01 material is the best. The specific discharge capacity at 0.1C, 0.2C, 0.5C, 1C and 0.1C are 182, 148.3, 123.5, 110.3 and 125.8 mAh/g, respectively. •Almost no one has made a positive electrode material co-doped with Al3+ and Zr4+.•Zr4+ doped materials are compared with Al3+-Zr4+ co-doped materials at characteristics.•The Zr4+ doped cathode materials were synthesized and resulted in an enhancement in the layer distance as well as better migration of lithium ions.•The initial discharge capacity of the material when the Zr4+ doping amount x = 0.01 was 199.0 mAh/g at 0.1 C.•Found that co-doping did not further improve the electrochemical properties of the material, probably due to the electrochemical inertness of Al.