Solid-State Battery Electrode Bonding for Stable Internal Resistance
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Solution Overview
Problem
Existing solid-state batteries face challenges in suppressing the increase in internal resistance due to the volume changes of negative electrode active materials like Si during charging/discharging, leading to separation of the collector and electrode layers.
Innovation Solution
Incorporating a resin layer between the negative electrode collector and the electrode layer, where the active material resin and resin layer share a common structure, allowing them to adhere and anchor together, thereby preventing separation and maintaining electrical contact despite volume changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a negative electrode active material with high capacity (such as Si) is used, then the battery capacity is improved, but the internal resistance increases greatly due to volume changes during charging/discharging
Solution Approach 1:
The patent uses composite particles consisting of Si particles combined with carbon particles or alloy particles. The carbon or alloy component provides structural stability during volume changes, while the Si provides high capacity. This composite structure prevents the internal resistance increase that would occur with pure Si alone.
Solution Approach 2:
The patent modifies the particle structure by creating composite particles with specific size distributions and compositions. By changing the physical parameters of the active material (particle size, composition ratio, structural configuration), the material can accommodate volume changes without increasing internal resistance.
2Reliability
If composite particles with binder and Si/Sn particles are used, then cycling characteristics deterioration is suppressed, but the complexity of electrode layer structure increases
Solution Approach 1:
The patent combines the active material particles with binder material into integrated composite particles before forming the electrode layer. This merging of components at the particle level simplifies the overall electrode structure compared to using separate layers, while still providing the benefits of suppressing volume change deterioration.
3Reliability
If volume change of active material is suppressed, then internal resistance increase is reduced, but the ability to accommodate Li ions during charging/discharging is limited
Solution Approach 1:
The patent creates different regions within the composite particles with different properties. The Si or Sn core regions provide high Li ion capacity and volume change, while the surrounding carbon or alloy regions provide structural stability and resist volume change. This local differentiation allows simultaneous achievement of high capacity and stable internal resistance.
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 effectively suppresses the increase in internal resistance during charging/discharging by ensuring the collector and electrode layers remain bonded, enhancing the cycling characteristics of the battery.
Implementation Method 1
the active material resin and the resin layer have a structure in common, allowing them to adhere and anchor together
Data Source
AI summary
A solid-state battery has a first collector, a first electrode layer, an electrolyte layer, a second electrode layer and a second collector in that order, wherein the first collector includes a resin layer that contacts the first electrode layer, the first electrode layer contains an electrode active material, and the electrode active material has an active material resin.