Improvement of float charge durability for LiCoO2 electrodes under high voltage and storage temperature by suppressing O1-Phase transition

Hierarchical Defect Engineering for LiCoO2 through Low-Solubility Trace Element Doping

“…As shown in Fig- ure 5C, the changes of both the cell-lattice parameters a and c and the cell volume of TLCO are smaller than those of the bare LCO, which strongly demonstrates the significant suppression of the phase transition in TLCO. In connection with the aforementioned analysis of the diffraction images, it can be hinted that the multimodular defects induced by the low solubility of Ti, in addition to homogeneous Al/Mg lattice doping, 24,35 can well suppress the collective O 3 to H 1À3 phase transition occurring in the bare LCO. Such an effect can partially contribute to the greatly enhanced cycle performances of TLCO at 4.6 V. The underlying mechanism can be understood as shown in Figure 5D, which schematically compares the lattice defect density (top) and the microstrain distribution (bottom) in primary grains of LCO and TLCO crystal.…”

An Overview on the Advances of LiCoO2 Cathodes for Lithium‐Ion Batteries

“…[ 101 ] These results were further supported by experiments. [ 72,86,101,102 ] Zhou et al's calculation results showed that the halogen species in oxygen sites enlarge the lithium slabs, improve the lithium storage capacity, increase the lithium diffusion, and decrease the lattice and volume change during the (de)lithiation process. [ 95 ] Ouyang et al's calculation found that the electrical conductivity can be improved upon Li + doping in Co 3+ sites.…”

Advancing to 4.6 V Review and Prospect in Developing High‐Energy‐Density LiCoO2 Cathode for Lithium‐Ion Batteries

“…As the LCO cathode was charged to high voltages, O1 phase started to emerge as evidenced by diffraction spots in the illustration of Figure 2a. Unstable O1 phase decomposes into a spinel structure, accompanied by the release of oxygen and the dissolution of Co. [ 48–50 ] The atomic resolution image of Figure 2b reveals how the layered structure evolves with the cycle number increases under high voltage. Combined with the electrochemical test (Figure 2c), it is concluded that the degradation of the bulk structure keeps pace with the capacity attenuation under the effect of voltage variation and cycle number growth, indicating that the bulk failure is one of the main reasons for the capacity loss.…”

“…As the LCO cathode was charged to high voltages, O1 phase started to emerge as evidenced by diffraction spots in the illustration of Figure 2a. Unstable O1 phase decomposes into a spinel structure, accompanied by the release of oxygen and the dissolution of Co. [48][49][50] The atomic resolution image of Figure 2b reveals how the layered structure evolves with the cycle number increases under high voltage. Reproduced with permission.…”