Solid-State Battery Anode Composite for Volume-Change Stability
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Solution Overview
Problem
Existing all-solid secondary batteries face challenges with volume changes during charging and discharging, leading to reduced cycling performance and potential safety issues due to the use of liquid electrolytes.
Innovation Solution
The development of an all-solid secondary battery that incorporates a composite anode active material, comprising a metal oxide and a carbon-based material, which is dispersed within a matrix of the carbon-based material, thereby reducing volume changes and suppressing irregular electrode reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional anode active material is used in an all-solid secondary battery, then the battery can operate with solid electrolyte, but volume changes during charging and discharging occur leading to reduced cycling performance
Solution Approach 1:
The patent applies composite materials by combining metal oxide particles with a carbon-based material matrix. The carbon-based material accommodates the volume changes of the metal oxide during lithium insertion and extraction, while the metal oxide provides high capacity. This composite structure resolves the contradiction by maintaining structural integrity during volume changes, thereby improving cycling performance while allowing the use of high-capacity metal oxide anodes.
2Reliability
If liquid electrolytes are used in lithium batteries, then the batteries can provide sufficient ionic conductivity, but the risk of fire or explosion increases
Solution Approach 1:
The patent applies parameter changes by transitioning the electrolyte from liquid state to solid state. This fundamental parameter change eliminates the fire and explosion risks associated with liquid electrolytes while maintaining ionic conductivity through the solid electrolyte. The solid electrolyte provides both safety improvement and sufficient ionic transport for battery operation.
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 use of the composite anode active material enhances the cycling performance of the all-solid secondary battery by accommodating volume changes and reducing side reactions, thereby improving safety and stability.
Implementation Method 1
the composite anode active material includes a metal oxide and a carbon-based material, which may be dispersed within a matrix of the carbon-based material... has suppressed or reduced volume changes during charging and discharging
Implementation Method 2
All-solid secondary batteries, which employ solid electrolytes instead of liquid electrolytes, have been proposed. Compared to liquid electrolytes, solid electrolytes may be relatively less likely to cause fires.
Data Source
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AI summary
An all-solid secondary battery including a cathode layer, an anode layer, and an electrolyte layer between the cathode layer and the anode layer, wherein the cathode layer includes a cathode current collector and a cathode active material layer on one surface of the cathode current collector, the anode layer includes an anode current collector and a first anode active material layer on one surface of the anode current collector, the first anode active material layer includes a composite anode active material, the composite anode active material includes a first metal oxide represented by MaOb (0<a≤3 and 0<b<4, wherein if a is 1, 2, or 3, b is not an integer) and a carbon-based material, the first metal oxide is within a matrix of the carbon-based material, and M is one or more metals selected from metals in Groups 2 to 12 and 14 to 16.