Synthesis Method for Long Cycle Life Lithium-Ion Cathode Material: Nickel-Rich Core–Shell LiNi_0.8Co_0.1Mn_0.1O₂

Abstract

High-nickel materials with core-shell structures, whose bulk is rich in nickel content and the outer shell is rich in manganese content, have been demonstrated to improve cycle stability. The high-nickel cathode material LiNiCoMnO is a very promising material for lithium-ion batteries; however, its low rate performance and especially cycle performance currently hamper further commercialization. This study presents a new synthesis method to prepare this core-shell material (LiNiCoMnO@ x[Li-Mn-O], x = 0.01, 0.03, 0.06). Electrochemical data show that LiNiCoMnO@ x[Li-Mn-O] ( x = 0.03, CS-0.03) exhibits the best high-rate performance, cycle stability, and thermal stability. The initial discharge capacity of the core-shell sample CS-0.03 is 118 mAh g, which is almost the same as the discharge capacity of pristine LiNiMnCoO (117 mAh g) at the rate of 10 C in the voltage range of 3.0-4.3 V. Notably the capacity decay of CS-0.03 is 18.4% after 200 cycles compared to 27% decay in capacity of the pristine sample. Furthermore, CS-0.03 exhibits better thermal cycling stability. The capacity retention of the CS-0.03 sample reached 65.1% which is over 1.3 times than that of the pristine one, whose capacity retention is 49.2% after 105 cycles (55 °C). Evidently, the core-shell structured CS-0.03 sample has excellent cycle stability and this synthesis method can be applied to other cathode materials.

Surface-Coated LiNi0.8Co0.1Mn0.1O2 (NCM811) Cathode Materials by Al2O3, ZrO2, and Li2O-2B2O3 Thin-Layers for Improving the Performance of Lithium Ion Batteries

“…In order to further increase energy densities of the devices, high-nickel NCM-based materials such as LiNi x Co y Mn z O 2 (here x+y+z = 1 with x>y+z) family have been explored and used in LIBs. It seems that one of the most promising LIB cathode materials is LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811, where x = 0.8, y = 0.1, and z = 0.1), which shows higher specific capacity than other family members (Cao et al, 2018;Li Q. et al, 2018).…”

Core–Shell Structure and X‐Doped (X = Li, Zr) Comodified O3‐NaNi0.5Mn0.5O2: Excellent Electrochemical Performance as Cathode Materials of Sodium‐Ion Batteries

“…Furthermore, high manganese concentration spinel shell provides 3D sodium‐ion diffusion channels to promote sodium‐ion transport . The Columbic efficiencies of first cycle for the pristine sample and the other three samples that have different concentrations of Mn 4+ in the shell are shown in Figure e.…”

Research Progress on the Surface of High-Nickel Nickel–Cobalt–Manganese Ternary Cathode Materials: A Mini Review

“…A material synthesized by the co-precipitation method has a small and uniform particle size and is typically used for coating the high-nickel NCM ternary cathode material and for the synthesis of the core-shell structure. For example, the following are prepared by co-precipitation method: LiNi 0.6 Mn 0.2 Co 0.2 O 2 (Ren et al, 2017 ), LiNi 0.8 Mn 0.8 Co 0.1 O@Li 3 PO 4 @PPy (Chen S. et al, 2017 ), Li[(Ni 0.8 Co 0.1 Mn 0.1 ) 1−x (Ni 0.5 Mn 0.5 ) x ]O 2 (Sun et al, 2006a ), LiNi 0.8 Co 0.1 Mn 0.1 O 2 @x[Li-Mn-O] (Li et al, 2018 ), and LiNi 0.8 Co 0.1 Mn 0.1 O 2 @active material core-shell material (Su et al, 2019 ). High temperature solid phase method is typically used for doping modification, as follows: Ca doping LiNi 0.8(1−x) Co 0.1 Mn 0.1 Ca 0.8x O 2 (Chen M. et al, 2017 ), Mn doping LiNi 0.82−x Co 0.12−x Mn 0.06+2x O 2 (Cho et al, 2018 ), and Mo doping LiNi 0.6 Co 0.2 Mn 0.2 O 2 (Xue et al, 2018 ).…”