Progressive concentration gradient nickel-rich oxide cathode material for high-energy and long-life lithium-ion batteries

Abstract

A novel progressive concentration gradient cathode material, LiNi0.7Co0.13Mn0.17O2, with superior capacity and cycling stability is reported for the first time.

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

“…The structural mismatch will obstruct the Li + transportation and electron transfer, leading to the decline in electrochemical properties . In order to overcome this weakness, Yin et al innovatively propose the FCG structure, in which the TM ions increase and/or decrease successively from the center zone to outer surface …”

“…For this phenomenon, Dahn and co‐workers elaborately conduct a series of experiments to measure the interdiffusivity of TM ions based on binary systems (Ni 3+ /Co 3+ , Co 3+ /Mn 4+ , and Ni 3+ /Mn 4+ ) at different high sintering temperatures, demonstrating that the Ni 3+ /Co 3+ has the highest interdiffusion coefficient while the Ni 3+ /Mn 4+ possesses the smallest one . In order to weaken the interdiffusion influence and tackle the poor cycling stability of Ni‐rich cathode (LiNi 0.7 Co 0.13 Mn 0.17 O 2 ), a progressively increasing TM variation rate (decrease in Ni, increases in Co and Mn) from core to surface is successfully realized . As a consequence, the average Ni content can be maximized while maintaining a stable Mn, Co‐rich surface layer.…”

Development of Novel Cathode with Large Lithium Storage Mechanism Based on Pyrophosphate‐Based Conversion Reaction for Rechargeable Lithium Batteries

“…For 200 cycles at 1C, the full‐cell exhibited outstanding capacity retention of ≈68% compared with its initial specific capacity. In addition, Table S3 (Supporting Information) showed electrochemical performance of nano‐C–CPO compared to other cathode materials for LIBs . The results indicate that nano‐C–CPO can be considered a promising cathode for high‐energy LIBs.…”

New Insight into the Role of Mn Doping on the Bulk Structure Stability and Interfacial Stability of Ni‐Rich Layered Oxide

“…[9,10] The irreversible structural transformations of surface and bulk phase can reduce active-mass/lithium and increase the interface resistance. [11] To overcome the performance degradation of nickel-rich materials, several strategies including lattice doping (Na + , Mg 2 + , Al 3 + , Ti 4 + , Zr 4 + , Mo 6 + , W 6 + ), [12][13][14][15][16][17][18] surface coating (Graphene, ZrO 2 , CeO 2 , MoS 2 , LiZr (PO 4 ) 3 ), [19][20][21][22][23] and structure design [24,25] have been proposed and demonstrated. Among these approaches, fabricating a cation mixing pillar layer has recently been considered as a valid approach to obtain a stable surface structure.…”