Battery Electrode-Separator Bonding via Mg2+ Coordination Crosslinking
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Solution Overview
Problem
The formation of an SEI film during the initial charging process consumes a significant amount of active lithium, leading to low initial efficiency and reduced energy density in batteries, particularly in negative electrodes with materials like silicon, and results in poor binding strength between the negative electrode and the separator, causing deformation during cycling.
Innovation Solution
Incorporating a functional layer with Mg2+ embedded in the negative active substance layer and a polymer material in the separator coating layer that performs a coordination crosslinking reaction, enhancing the binding strength between the negative electrode plate and the separator, while improving ionic conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional negative electrode is used without functional layer modification, then the battery structure is simple, but the initial efficiency is low due to SEI film formation consuming active lithium
Solution Approach 1:
The patent applies preliminary action by pre-embedding magnesium ions (Mg2+) and polymer materials into the negative electrode structure before battery operation. The Mg2+ ions are incorporated into the negative active substance layer, and the polymer material is coated on the separator surface facing the negative electrode, both prepared in advance to enable coordination crosslinking reactions that will occur during initial charging, thereby improving initial efficiency without requiring structural changes during battery operation.
Solution Approach 2:
The patent uses polymer material as an intermediary substance between the separator and the negative electrode. This polymer material contains functional groups that can coordinate with Mg2+ ions, forming a coordination crosslinked network that acts as a mediator to enhance the binding strength between the negative electrode and separator, while also improving ionic conductivity and initial efficiency.
2Reliability
If the binding strength between negative electrode and separator is weak, then the battery manufacturing is easier, but the battery deforms during cycling
Solution Approach 1:
The patent employs composite materials by combining the separator base material with a polymer coating layer that contains coordination crosslinking functional groups. This composite structure integrates the mechanical properties of the base separator with the bonding and ionic conductivity enhancement provided by the polymer coating, creating a multi-functional separator that improves structural stability while maintaining ease of manufacture.
Solution Approach 2:
The patent applies parameter changes by modifying the chemical properties of the separator surface through polymer coating. The polymer material introduces functional groups capable of coordination crosslinking with Mg2+ ions, which changes the chemical bonding parameters at the negative electrode-separator interface, thereby enhancing binding strength and structural stability during battery cycling.
3Strength
If polymer material with coordination crosslinking capability is added to the separator, then the binding strength and ionic conductivity improve, but the separator manufacturing complexity increases
Solution Approach 1:
The patent applies local quality by concentrating the polymer material and coordination crosslinking functional groups specifically at the surface of the separator that contacts the negative electrode. The bulk of the separator retains its original simple structure for ease of manufacture, while only the functional surface layer is modified with the polymer coating, providing enhanced peel strength and ionic conductivity locally where needed without complicating the overall separator 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
This design increases the initial efficiency and peel strength of the negative electrode, reduces internal resistance, and enhances fast charging performance by improving the bonding and ionic conductivity of the battery.
Implementation Method 1
the polymer material in the coating layer performs a coordination crosslinking reaction with the Mg2+
Data Source
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AI summary
This application provides a battery, including a negative electrode plate and a separator. The negative electrode plate includes a negative active substance layer and a functional layer that are stacked. The functional layer includes Mg2+, where some of the Mg2+ is embedded in the negative active substance layer. The separator includes a base film and a coating layer located on a surface of the base film, and the coating layer bonds the base film and the functional layer. The coating layer includes a polymer material. The polymer material is coordination-crosslinked with at least some of the remaining Mg2+ in the functional layer. The polymer material in the coating layer performs a coordination crosslinking reaction with the Mg2+ in the functional layer, so as to effectively increase binding strength between the negative electrode plate and the separator, thereby helping prevent deformation of the battery during a cycle process. In addition, after ionization of the polymer material, ionic conductivity performance of the polymer material can be effectively improved, and internal resistance of the battery is reduced, thereby improving fast charging performance of the battery. This application further provides a terminal apparatus including a battery and a method for manufacturing a battery.