All-Solid Battery Anode Layering for Uniform Lithium Deposition
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Solution Overview
Problem
All-solid secondary batteries face challenges with short-circuits and reduced cycle characteristics due to lithium deposition and reductive decomposition of the solid electrolyte during charging and discharging, which can lead to safety issues and decreased performance.
Innovation Solution
The battery design includes a cathode layer, an anode layer, and a solid electrolyte layer with a first anode active material layer having a lithium-ion reduction potential greater than the solid electrolyte's reduction potential, and a second anode active material layer with higher lithium solubility, which suppresses reductive decomposition and ensures uniform lithium deposition, thereby preventing short-circuits and improving cycle characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If lithium metal is used as a negative electrode for high energy density, then capacity is improved, but lithium deposition and dendrite formation cause short-circuits during charging and discharging
Solution Approach 1:
The negative electrode layer acts as a mediator between the solid electrolyte and lithium metal, providing a controlled interface for lithium deposition. This intermediate structure guides lithium ion distribution and prevents uncontrolled dendrite growth, thereby maintaining high capacity while preventing short-circuits.
Solution Approach 2:
The negative electrode layer introduces spatial variation in lithium deposition characteristics. By controlling the local properties of the negative electrode layer, uniform lithium distribution is achieved, preventing localized dendrite formation while maintaining overall high lithium capacity.
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 configuration enhances the stability of the solid electrolyte, prevents short-circuits, and improves the battery's cycle performance by facilitating reversible lithium deposition and dissolution, leading to improved safety and efficiency.
Implementation Method 1
a first anode active material layer in contact with the solid electrolyte layer, and a second anode active material layer disposed between the anode current collector and the first anode active material layer, wherein the first anode active material layer comprises a first metal and has a lithium-ion reduction potential greater than a reduction potential of the solid electrolyte
Implementation Method 2
a second anode active material layer disposed between the anode current collector and the first anode active material layer wherein the second anode active material layer comprises a second metal, and a solid solubility of lithium in the second metal is greater than a solid solubility of lithium in the first metal
Implementation Method 3
the negative electrode is capable of participating in an alloy reaction with lithium or has a lithium solubility
Data Source
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AI summary
An all-solid secondary battery including: a cathode layer including a cathode active material; an anode layer; and a solid electrolyte layer including a solid electrolyte disposed between the cathode layer and the anode layer, wherein the anode layer includes an anode current collector, a first anode active material layer in contact with the solid electrolyte layer, and a second anode active material layer disposed between the anode current collector and the first anode active material layer, wherein the first anode active material layer includes a first metal and has a lithium-ion reduction potential greater than a reduction potential of the solid electrolyte, and wherein the second anode active material layer includes a second metal, and a solid solubility of lithium (Li) in the second metal is greater than a solid solubility of lithium in the first metal.