Nasicon-Type Surface Functional Modification in Core–Shell LiNi_0.5Mn_0.3Co_0.2O₂@NaTi₂(PO₄)₃ Cathode Enhances Its High-Voltage Cycling Stability and Rate Capacity toward Li-Ion Batteries

Abstract

Surface modifications are established well as efficient methodologies to enhance comprehensive Li-storage behaviors of the cathodes and play a significant role in cutting edge innovations toward lithium-ion batteries (LIBs). Herein, we first logically devised a pilot-scale coating strategy to integrate solid-state electrolyte NaTi(PO) (NTP) and layered LiNiMnCoO (NMC) for smart construction of core-shell NMC@NTP cathodes. The Nasicon-type NTP nanoshell with exceptional ion conductivity effectively suppressed gradual encroachment and/or loss of electroactive NMC, guaranteed stable phase interfaces, and meanwhile rendered small sur-/interfacial electron/ion-diffusion resistance. By benefiting from immanently promoting contributions of the nano-NTP coating, the as-fabricated core-shell NMC@NTP architectures were competitively endowed with superior high-voltage cyclic stabilities and rate capacities within larger electrochemical window from 3.0 to 4.6 V when utilized as advanced cathodes for advanced LIBs. More meaningfully, the appealing electrode design concept proposed here will exert significant impact upon further constructing other high-voltage Ni-based cathodes for high-energy/power LIBs.

Electrochemically Modulated LiNi1/3Mn1/3Co1/3O2 Cathodes for Lithium‐Ion Batteries

“…The relationship between Z′ and ω −1/2 profiles is presented in Figure e and D Li+ values are calculated in Table . Obviously, fresh electrode showed a larger D Li+ value (1.47 × 10 −13 cm 2 s −1 ) than after 120 cycles electrode (1.03 × 10 −13 cm 2 s −1 ), indicating the decrease of active lithium with the increase of cycle times due to that the interface of electrode after 120 cycles was readily covered by an insulative Li‐based residue layer …”

Rechargeable Lithium Metal Batteries with an In‐Built Solid‐State Polymer Electrolyte and a High Voltage/Loading Ni‐Rich Layered Cathode

“…To mitigate these problems, high‐voltage stable molecules such as carbonates are generally introduced 29. Artificial cathode–electrolyte interphases (CEI) produced by coating the active cathode materials with desirable compounds such as organophosphates,30 polypyrrole (PPy),31 phosphate polyanion,32 Al 2 O 3 ,33 and NaTi 2 (PO 4 ) 3 34 have also been reported to protect the cathode. However, the most successful coating strategies are demonstrated in carbonate‐based liquid electrolytes, which introduce new stability challenges when the cathodes are paired with high‐energy alkali metal anodes.…”

Surface/Interface Structure Degradation of Ni‐Rich Layered Oxide Cathodes toward Lithium‐Ion Batteries: Fundamental Mechanisms and Remedying Strategies

“…In this respect, we integrate the solid‐state electrolyte NaTi 2 (PO 4 ) 3 with exceptional ion conductivity and Ni‐rich cathodes to construct core–shell structure. The NaTi 2 (PO 4 ) 3 coating layer not only can effectively ensure the stable phase interfaces but also render small surface/interface electron/ion‐diffusion resistances …”

“…To date, nickel‐rich (Ni‐rich) layered cathode materials, specifically for the LiNi x Co y Mn z O 2 (NCM) and LiNi x Co y Al z O 2 (NCA), represent the most competitive candidates for the practical utilization of LIBs in full consideration of the gravimetric capacity, rate capability, and cost efficiency . Presently, the Ni‐rich cathodes with nickel content less than 60% have been widely and successfully commercialized in LIBs . Nevertheless, there still are many troubles in the commercialization for the case of nickel content ≥80% in terms of the potential safety issues and processability during the electrode fabrication .…”