Oxide-Nitride Current Collector for Anion-Resistant Batteries
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Solution Overview
Problem
Secondary batteries face issues with corrosion of electrode materials due to anion reactions in the electrolyte solution, leading to deteriorated cycle life, storage performance, and safety, especially in sodium secondary batteries with no negative electrode.
Innovation Solution
A current collector with a metal substrate and a surface treatment layer comprising oxide and/or nitride of the metal substrate, which protects against anion corrosion, enhances high-voltage tolerance, and improves coulombic efficiency and cycle capacity retention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metal current collector is used in secondary batteries, then good electronic conductivity is achieved, but the metal substrate is corroded by anions in the electrolyte solution leading to deteriorated cycle life and storage performance
Solution Approach 1:
The patent applies the intermediary principle by introducing a surface treatment layer comprising oxide and/or nitride of the metal substrate as a protective mediator between the metal current collector and the electrolyte solution. This intermediate layer prevents direct contact between harmful anions and the metal substrate, thereby eliminating corrosion while maintaining the underlying good electronic conductivity of the metal current collector.
Solution Approach 2:
The patent employs composite materials by creating a composite structure where a metal substrate is combined with a surface treatment layer of oxide and/or nitride. This composite current collector integrates the high conductivity of the metal with the protective and chemically stable properties of the oxide/nitride layer, resolving the contradiction between conductivity and corrosion resistance.
2Object-affected harmful factors
If the surface treatment layer thickness is increased to improve corrosion protection, then anion corrosion resistance is enhanced, but electronic conductivity is affected and internal resistance increases
Solution Approach 1:
The patent applies parameter changes by precisely controlling the thickness of the surface treatment layer within the range of 1 nm to 200 nm. This optimized thickness parameter provides sufficient corrosion protection while maintaining adequate electronic conductivity. Additionally, the patent specifies that the metal substrate thickness should be 5 μm to 100 μm to ensure low internal resistance while providing structural stability.
Solution Approach 2:
The patent applies local quality by creating a surface treatment layer with specific local properties (oxide/nitride composition and controlled thickness) only where needed for corrosion protection, while the bulk metal substrate maintains its high conductivity properties. This localized treatment ensures protection where required without compromising the overall electronic conductivity of the current collector.
3Reliability
If heat treatment is used to form the surface treatment layer, then corrosion protection and high-voltage tolerance are enhanced, but the process complexity increases
Solution Approach 1:
The patent applies self-service by utilizing heat treatment to form the protective surface treatment layer through a self-organizing process where the metal substrate itself generates the protective oxide/nitride layer when exposed to controlled heating conditions. This self-service approach eliminates the need for separate coating processes or additional materials, simplifying the overall manufacturing process while achieving the desired protective properties.
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 surface treatment layer effectively prevents corrosion, enhances the current collector's tolerance under high voltage, and improves the battery's coulombic efficiency, cycle capacity retention, and storage performance without affecting electronic conductivity.
Implementation Method 1
the surface treatment layer can protect the metal from corrosion by anions in the electrolyte solution
Implementation Method 2
enhance the tolerance of the current collector under high voltage
Implementation Method 3
the surface treatment layer includes oxide and/or nitride of the metal substrate
Implementation Method 4
the surface treatment layer includes oxide and/or nitride of the metal substrate
Data Source
AI summary
This application provides a current collector and a preparation method thereof, a secondary battery, a battery module, a battery pack, and an electric apparatus. The current collector includes a metal substrate and a surface treatment layer formed on at least one side of the metal substrate, where the surface treatment layer includes oxide and/or nitride of the metal substrate. The surface treatment layer can protect the metal from corrosion by anions in the electrolyte solution or optimize the metal nucleation behavior, improve the coulombic efficiency and cycle capacity retention rate of the battery, and improve the storage performance of the battery.