Effect of Nb and F Co-doping on Li1.2Mn0.54Ni0.13Co0.13O2 Cathode Material for High-Performance Lithium-Ion Batteries

Abstract

The Li1.2Mn0.54−xNbxCo0.13Ni0.13O2−6xF6x (x = 0, 0.01, 0.03, 0.05) is prepared by traditional solid-phase method, and the Nb and F ions are successfully doped into Mn and O sites of layered materials Li1.2Mn0.54Co0.13Ni0.13O2, respectively. The incorporating Nb ion in Mn site can effectively restrain the migration of transition metal ions during long-term cycling, and keep the stability of the crystal structure. The Li1.2Mn0.54−xNbxCo0.13Ni0.13O2−6xF6x shows suppressed voltage fade and higher capacity retention of 98.1% after 200 cycles at rate of 1 C. The replacement of O2− by the strongly electronegative F− is beneficial for suppressed the structure change of Li2MnO3 from the eliminating of oxygen in initial charge process. Therefore, the initial coulombic efficiency of doped Li1.2Mn0.54−xNbxCo0.13Ni0.13O2−6xF6x gets improved, which is higher than that of pure Li1.2Mn0.54Co0.13Ni0.13O2. In addition, the Nb and F co-doping can effectively enhance the transfer of lithium-ion and electrons, and thus improving rate performance.

Formation of Pillar-Ions in the Li Layer Decreasing the Li/Ni Disorder and Improving the Structural Stability of Cation-Doped Ni-Rich LiNi0.8Co0.1Mn0.1O2: A First-Principles Verification

“…To control the degradation problem, morphology control, core–shell design, surface coating, and doping with foreign elements have been carried out. − Among these, doping is one of the fundamental approaches that effectively suppress the disorderly mixing of Ni 3+ -ions. Thus far, monovalent (Ag + and Na + ), divalent (Ca 2+ , Fe 2+ , Mg 2+ , V 2+ , Cu 2+ , and Zn 2+ ), trivalent (Al 3+ , Ga 3+ , Nb 3+ , and Ti 3+ ), and tetravalent (Mo 4+ , Sn 4+ , and Zr 4+ ) cations have been used in the various Ni, Co, and Mn compositions of layered NCM cathode materials. ,− These dopants prevent Ni 3+ -ion mixing at the Li layer of active materials under a high operating voltage. The Ga 3+ , Zr 4+ , and Mo 4+ dopants substituted at the Ni site decrease the concentration of JT active Ni 3+ ions and reduce cation disorder in the Ni-rich NCM materials. ,, …”

Fluorine Doping Induced Crystal Space Change and Performance Improvement of Single Crystalline LiNi0.6Co0.2Mn0.2O2 Layered Cathode Materials

“…[25,[26][27][28] The Co 2p spectra are composed of the Co 2p 3/2 peaks (including the corresponding satellite peak) and Co 2p 1/2 peak, while the Co 2p 3/2 peak includes the Co 3 + and Co 2 + peaks located at respectively 780.1 and 782.5 eV. [28][29][30][31] The Mn 2p spectra consist of the Mn 2p 3/2 peak at 642.6 eV and the Mn 2p 1/2 peak at 654.0 eV, respectively. [31] Compared the samples before and after fluoride doping, the peak positions of Ni, Co and Mn in the XPS spectra do not change significantly, and only the peak strength and peak shape change slightly.…”

“…[28][29][30][31] The Mn 2p spectra consist of the Mn 2p 3/2 peak at 642.6 eV and the Mn 2p 1/2 peak at 654.0 eV, respectively. [31] Compared the samples before and after fluoride doping, the peak positions of Ni, Co and Mn in the XPS spectra do not change significantly, and only the peak strength and peak shape change slightly. With the increase of the doping amount of fluorine, the content of Ni 2 + and Co 3 + increases, which is probably related to the partial reduction of the transition metal ion caused by the charge compensation at the O site in the F substituted material.…”

Baterias de íons lítio para veículos elétricos

“…Compostos como o Li-Nb-Fe-PO 4 com diversas estequiometrias aumentaram a condutividade eletrônica em todas as quantidades adicionadas de nióbio, 0,1 % atômica , 0,5 % atômica e 1,0 % atômica (CHUNG;BLOKING;CHIANG, 2002). Ming et al (2018) estudaram o efeito da adição de nióbio e flúor ao material catódico composto por LiMnNiCoO 2 . O material foi dopado com nióbio e flúor em diversas proporções, a saber, Li 1,2 Mn 0'54−x Nb x Co 0,13 Ni 0,13 O 2−6x F 6x (x = 0; 0,01; 0,03 e 0,05).…”