Enhanced Electrochemical and Structural Stability of Ni‐rich Cathode Material by Lithium Metaborate Coating for Lithium‐Ion Batteries

Abstract

A facile mechanical mixing‐calcination method was employed to coat lithium metaborate onto LiNi0.88Co0.06Mn0.03Al0.03O2 cathode. Physical characterizations revealed that the coating layer was uniformly spread on the surface of the material particles, and did not alter the structure and morphology. Electrochemical measurements indicated that the surface‐modified cathode showed significantly improved cycling stability, both under room‐temperature and high‐temperature (50 °C). The coated sample delivered an initial discharge capacity of 211.0 mAh g−1 at 0.1 C, and a capacity retention of 87.5 % after 300 cycles at 1 C rate under room‐temperature. Meanwhile, it could maintain 97.2 % of initial capacity after 120 cycles at 1 C under 50 °C, which was much higher than the value of the pristine sample (only 37.2 %). The lithium‐ion diffusion kinetics was analyzed by electrochemical impedance spectroscopy. The coated material exhibits lower surface resistance and charge‐transfer resistance, as well as faster lithium‐ion diffusion than the pristine one. The materials were also characterized after cycling. The surface‐modified sample possessed more stable surficial and structural stability.

Developments in Surface/Interface Engineering of Ni‐Rich Layered Cathode Materials

“…Similarly, Zhao et al. successfully coated lithium metaborate layer of Ni‐rich particles (NCMA88@0.2B) through ball milling the layered oxides with H 3 BO 3 and later‐on calcination process [74] . The uniform lithium metaborate coating prevented the formation of the rock salt phase with a stable CEI layer, which not only kept the integrity of the structure but also promoted the Li + ions transport of the Ni‐rich particles.…”

“…Similarly, Zhao et al successfully coated lithium metaborate layer of Ni-rich particles (NCMA88@0.2B) through ball milling the layered oxides with H 3 BO 3 and later-on calcination process. [74] The uniform Reproduced with permission. [71] Copyright 2017, Elsevier.…”

Review of Boron Compounds in Lithium Batteries: Electrolyte, Anode, Cathode, Separator, and Battery Thermal Management System (BTMS)

“…In the NMCA system of LiNi0.88Co0.06Mn0.03Al0.03O2, an LBO coating was applied for chemical stability and structural stability during the charge/discharge cycle, which in turn improved cycling performance significantly [105].…”

In Situ Formation of a LiBO2 Coating Layer and Spinel Phase for Ni-Rich Cathode Materials from a Boric Acid-Etched Precursor

“…Boron and its compounds exhibit a very positive effect in enhancing the electrochemical performance of Ni-rich cathode material either by doping or coating. − According to the previous reports, boron, as a dopant, can modify the surface energies and offer strong B–O bonds, which results in radially aligned primary particles and less oxygen release. , As for the coating agent, LiBO 2 is the most adopted lithium-containing boron compound. , It is considered as an excellent coating material owing to its high ionic conductivity (∼10 –5 S·cm –1 ), chemical inertness, and electrochemical stability (up to 4.4 V). , Hence, these strategies can enhance the cycling performance and rate capability of the Ni-rich cathode material.…”