Nickel Cathode Hybrid Coating for Cycle and Thermal Stability
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Solution Overview
Problem
Conventional secondary batteries face challenges in meeting the increasing demands for improved cycle performance and dynamics performance, particularly in applications such as electric vehicles and energy storage systems.
Innovation Solution
A composite positive electrode material is developed, comprising a nickel-containing positive electrode material with a functional film layer containing Li2MO4 and a lithium organophosphonate compound, where M is sulfur, selenium, or tellurium, enhancing the structural stability, ionic conductivity, and thermal stability through an organic-inorganic hybrid film layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional positive electrode material is used, then the manufacturing process is simple, but the cycle performance and dynamics performance are insufficient
Solution Approach 1:
The patent applies composite materials by creating a functional film layer comprising both inorganic Li2MO4 and organic lithium organophosphonate compounds on the nickel-containing positive electrode material surface. This composite structure combines the advantages of both material types to achieve improved cycle performance and dynamics performance while managing structural complexity.
Solution Approach 2:
The patent implements local quality by forming a functional film layer specifically on the surface of the positive electrode material particles rather than modifying the bulk material. This localized approach targets the surface where electrochemical reactions occur, improving performance without unnecessarily complicating the overall structure.
2Stability of the object's composition
If the functional film layer is made thicker to improve stability, then the structural stability improves, but the ionic conductivity decreases
Solution Approach 1:
The patent uses composite materials in the functional film layer, combining Li2MO4 and lithium organophosphonate compounds in specific ratios. This composite structure provides both structural stability and maintains ionic conductivity through the synergistic effects of the different materials, avoiding the trade-off that would occur with a single-material thick film.
Solution Approach 2:
The patent applies parameter changes by controlling the thickness of the functional film layer to be within a specific range (5-20 nm) and adjusting the molar ratio of Li2MO4 to lithium organophosphonate compound (0.6 to 5):1. These parameter optimizations ensure the film is thick enough for stability but thin enough to maintain ionic conductivity.
3Ease of manufacture
If organic coating materials are used to improve flexibility, then the processing ease improves, but the thermal stability is insufficient
Solution Approach 1:
The patent combines organic lithium organophosphonate compounds with inorganic Li2MO4 in the functional film layer. The inorganic component provides the necessary thermal stability that organic materials alone cannot achieve, while the organic component maintains good coating processability and flexibility.
Solution Approach 2:
The patent uses lithium organophosphonate compounds as intermediary materials that bridge the organic-inorganic interface. These compounds facilitate the formation of a stable interface between organic and inorganic phases, improving both thermal stability and coating processability through their dual-characteristic molecular structure.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The composite positive electrode material improves cycling stability, dynamics performance, and thermal stability of secondary batteries, reducing the probability of fracture and enhancing overall battery performance.
Implementation Method 1
Li2MO4 and the organic component lithium organophosphonate compound can serve as fast-ionic conductors, effectively enhancing the dynamics performance of the positive electrode material
Implementation Method 2
the lithium organophosphonate compound exhibits good thermal stability performance and flame-retardant functions, which can enhance the thermal stability of the battery
Data Source
AI summary
A composite positive electrode material and a preparation method therefor, a positive electrode sheet, a battery, and an electrical apparatus. The composite positive electrode material comprises a nickel-containing positive electrode material and a functional film layer arranged on the surface of the nickel-containing positive electrode material. Components of the functional film layer comprise Li2MO4 and an organic lithium phosphonate compound, where M is selected from at least one of sulfur, selenium, and tellurium; and the organic lithium phosphonate compound contains a structure represented by formula (1):(I), where * represents sites where the structure represented by formula (1) is connected to other structures in the organic lithium phosphonate compound.