Synergy of doping and coating induced heterogeneous structure and concentration gradient in Ni-rich cathode for enhanced electrochemical performance

New Insight into the Role of Mn Doping on the Bulk Structure Stability and Interfacial Stability of Ni‐Rich Layered Oxide

“…As is illustrated by Figure (a,c), the XRD patterns at different voltages show layered structure with the change of (003) diffraction peaks. It can be seen that the (003) peak first moves to a lower angle until it reaches 4.1 V, and then shifts to a higher angle to 4.3 V. As previously mentioned, the change above 4.1 V is ascribed to the H 2 /H 3 irreversible phase transition, which would lead to significant cell volume change and microcracks . Especially, the position of the (003) peak of the pristine NCA changes much greater than that of the M0.01−NCA, which can be verified by the structure refinement results in Table S3 and Table S4.…”

“…It can be seen that the (003) peak first moves to a lower angle until it reaches 4.1 V, and then shifts to a higher angle to 4.3 V. As previously mentioned, the change above 4.1 V is ascribed to the H 2 /H 3 irreversible phase transition, which would lead to significant cell volume change and microcracks. [41] Especially, the position of the (003) peak of the pristine NCA changes much greater than that of the M0.01À NCA, which can be verified by the structure refinement results in Table S3 and Table S4. As is shown in Figure 7(b,d), the M0.01À NCA (1.1%) undergoes a smaller constriction of the c-axis parameter shrinkage at the end of charging (4.3 V) than that of the pristine NCA (1.8%), and the shrinkage of the cell volume for the M0.01À NCA (2.9%) is also smaller compared with the pristine NCA (3.7%).…”

Enhanced High‐Temperature Electrochemical Performance of Layered Nickel‐Rich Cathodes for Lithium‐Ion Batteries after LiF Surface Modification

“…[21][22][23] Moreover, the dissolution of metal ions is accelerated at high temperatures, causing the layered structure to collapse and the material's thermal stability to deteriorate. [24][25][26][27] To overcome these limitations, surface modification is one of most commonly employed routes, which can suppress side reactions at the electrode/electrolyte interface, thereby improving cycle stability. [28][29][30] Currently, many researches have discussed the coating of oxides, [31] phosphates, [32] carbon, [33] and fluoride.…”

“…HF produced by lithium hydroxide corrodes the electrode material, resulting in an irreversible phase change of the cathode . Moreover, the dissolution of metal ions is accelerated at high temperatures, causing the layered structure to collapse and the material's thermal stability to deteriorate …”

Structure and electrochemical performance modulation of a LiNi0.8Co0.1Mn0.1O2 cathode material by anion and cation co-doping for lithium ion batteries

“…As shown in Fig. 8, the clear peak shi of (003) and existence of peak in the dQ/dV indicate that NCM/CB electrode suffers from incessant phase transition including the phase of H1, M, H2 and H3 At the beginning, as the distance between the layers increases, an irreparable structural transition occurs from H1 to M with the increase of delithiation at 3.6-3.8 V. 39 At the same time, the (003) peak moves marginally to a lower angle. When further charged to 4.0 V, M and H2 phase are coexisted in the electrode, accompanying the change of (003) to a lower angle.…”