Realizing Superior Cycle Stability of a Ni‐Rich Layered LiNi_0.83Co_0.12Mn_0.05O₂ Cathode with a B₂O₃ Surface Modification

Abstract

Ni‐rich cathode is considered a promising cathode for its high specific capacity. However, a sharp capacity attenuation induced by interface problems limits the application of the cathode material. Herein, we propose a practical surface modification strategy by introducing diboron trioxide (B2O3) to the surface of LiNi0.83Co0.12Mn0.05O2 (NCM) cathode materials. B2O3‐modified NCM shows superior cyclic stability with a capacity retention of 87.7 % at 1 C after 200 cycles in comparison to 69.4 % for a bare NCM. On the basis of material and electrochemical characterizations, we conclude that the superior cycle stability of B2O3‐modified NCM material benefits from the formation of B2O3 coating and B3+ doping on the surface. The B2O3 coating layer that is confirmed by scanning and transmission electron microscopy can suppress surface side reactions and reduce the content of Li2CO3 on the surface. The B3+‐doping surface is verified by X‐ray diffraction and X‐ray photoelectron spectroscopy and triggers a reduction of a small amount of Ni3+ to Ni2+. Furthermore, the combination of surface B2O3 coating and B3+ doping inhibits the irreversible phase transitions and extension of microcracks in the NCM material. The above surface modification strategy provides a direction for the acquisition of long‐life cathode materials.

Stabilizing Ni‐Rich LiNi0.92Co0.06Al0.02O2 Cathodes by Boracic Polyanion and Tungsten Cation Co‐Doping for High‐Energy Lithium‐Ion Batteries

“…The extra B 1s peak (Figure d) demonstrates the presence of B on the surface of NCA92‐W‐B. In the W 4 f spectrum (Figure e), the binding energies of 35.1and 37.1 eV match the values of the W−O band …”

“…In the W 4 f spectrum (Figure 1e), the binding energies of 35.1and 37.1 eV match the values of the WÀ O band. [20] The SEM images (Figure 2a-c) show that all samples consist of spherical secondary particles, which are assembled with nanoscale primary crystal. No significant change in the average particle-sized is observed, but the primary particles of NCA92-W-B are tightly aggregated with a fuzzy and rough surface.…”

Stabilization of a 4.7 V High‐Voltage Nickel‐Rich Layered Oxide Cathode for Lithium‐Ion Batteries through Boron‐Based Surface Residual Lithium‐Tuned Interface Modification Engineering

“…Figure 1b compares the B 1s spectra of both samples that the 1-NCM@LBO material has the BÀ O peak (~191.8 eV), representing the B x O y species, while there is no evidence in the pristine SC-NCM material. [41,46] In the C 1s spectra (Figure 1c), the residual lithium (Li 2 CO 3 ), C=O, À CH 2 À , and CÀ H peaks are included, respectively, suggesting that the content of Li 2 CO 3 is decreased in the 1-NCM@LBO material. [29,37] Also, the binding energy of O 1s at 531.6 eV and 529.6 eV originates from the active oxygen species (O2-active) and lattice oxygen species (O2-lattice), further indicating that such interface modification does reduce the surface residual lithium (Figure 1d).…”

NCA, NCM811, and the Route to Ni-Richer Lithium-Ion Batteries

“…B 2 O 3 -coated LiNi 0.83 Co 0.12 Mn 0.05 O 2 showed superior cyclic stability with a capacity retention of 96.8% and 87.7 % at 1 C after 100 and 200 cycles, respectively, against 69.4 % after 200 cycles for the pristine sample [190]. This result was explained by the fact that B 3+ -doping surface triggers a reduction of a small amount of Ni 3+ to Ni 2+ , in addition to the fact that it inhibits the irreversible phase transitions and extension of microcracks in the NCM material.…”