Effect of Voltage Range and BiPO₄ Coating on the Electrochemical Properties of LiNi_0.8Co_0.15Al_0.05O₂

Abstract

BiPO4‐coated LiNi0.8Co0.15Al0.05O2 (NCA) cathode material is prepared by a precipitation method. Scanning electron microscope and X‐ray diffraction results demonstrate that the morphology and structure of NCA are not affected by BiPO4 layer. Transmission electron microscopy analysis indicates that the thickness of the layer is about 10 nm. Electrochemical properties of NCA and BiPO4‐coated NCA are investigated in different voltage ranges. The results show that the wider the charge and discharge cut‐off voltage is, the larger the specific capacity is, with the initial discharge capacity of 325.0 mAh g−1 within the voltage of 1.5‐4.8 V. The most significant discovery is the charge platform at 2.3‐2.5 V and the discharge platform at around 1.7 V, which accounts for the high capacity properties of NCA. Furthermore, the existence of BiPO4 coating helps to enhance the cycle performance of NCA.

Surface Modification of LiNi0.8Co0.15Al0.05O2 Particles via Li3PO4 Coating to Enable Aqueous Electrode Processing

“…The strong P−O‐bonding energy in the PO 4 3− ion gives metal phosphates high structural stability against chemical attack [22–24] . Various phosphate coatings such as Ni 3 (PO 4 ) 2 , [25] FePO 4 , [26] LiMnPO 4 , [27] MgHPO 4 , [28] BiPO 4 , [29] Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 , [30] Li 3 PO 4 , [23,31] Co 3 (PO 4 ) 2 , [32,33] LiFePO 4 , [34] and AlPO 4 [31,33,35] have been studied on NCA and resulted in improved electrochemical performance. However, to the best of the authors’ knowledge, a phosphate‐coated NCA has never been used in a combination with a water‐based electrode manufacturing process.…”

Surface-Coated NaNi0.815Co0.15Al0.035O2 Cathode-Based Sodium-Ion Batteries with Enhanced Performance

“…The surface coating is an effective method and the surface coating with metal oxide [Co 3 O 4 , MgO, Al 2 O 3 , , TiO 2 , and SiO 2 , metal phosphate [CePO 4 , AlPO 4 , Li 3 PO 4 , ,− FePO 4 , BiPO 4 , Co 3 (PO 4 ) 2 , NaPO 3 , and Ni 3 (PO 4 ) 2 , metal sulfide, carbon coating, polymer coating, and so on have been reported for Na as well as Li-based cathode materials. Also, the coating layer protects the surface structure by preventing the rogue reactions between the electrode and electrolyte, and it retains the crystal structure of the cathode during cyclability, which leads to long cyclic stability and better electrochemical performance.…”

Green and low-cost synthesis of LiNi0.8Co0.15Al0.05O2 cathode material for Li-ion batteries

“…Owing to the advantages in gravimetric capacity, rate capability and capital cost, LiNi 0.8 Co 0.15 Al 0.05 O 2 (NCA) has found relatively widespread commercial applications as a cathode material, for instance, in Panasonic batteries for Tesla electric vehicles [1][2][3]. To further enhance the electrochemical properties of NCA, various strategies have been proposed.…”