Silver-Composite Solid-State Battery Anode for Low-Pressure Capacity
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Solution Overview
Problem
Existing all-solid lithium secondary batteries face challenges in achieving high discharge capacity without applying high external pressure, which limits their energy density and stability.
Innovation Solution
The battery design incorporates a negative active material layer with silver (Ag) and amorphous carbon, where Ag is present in a range of 10 wt % to 100 wt % and the Ag amount per unit area is between 0.05 mg/cm2 and 5 mg/cm2, along with a sulfide-based solid electrolyte layer, allowing for lithium alloy formation without requiring high external pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high external pressure is applied to the battery, then discharge capacity may be improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent changes the material composition parameters of the negative active material layer by incorporating silver (Ag) in specific weight ratios (10-100 wt%) and controlling the amount per unit area (0.05-5 mg/cm2). This material parameter change enables the battery to achieve high discharge capacity without requiring high external pressure, thus resolving the contradiction between discharge capacity and device complexity.
Solution Approach 2:
The patent uses a composite negative active material layer containing both silver (Ag) and amorphous carbon. This composite material structure leverages the unique properties of silver (high electrical conductivity, alloy formation capability) and amorphous carbon (lithium insertion/extraction properties) to achieve high discharge capacity without requiring external pressure application systems.
2Quantity of substance
If lithium is used as negative active material to increase specific capacity, then energy density improves, but structural stability deteriorates without proper pressure control
Solution Approach 1:
The patent changes the compositional parameters by incorporating silver in controlled amounts (10-100 wt%) and specific distributions (0.05-5 mg/cm2 per unit area). This parameter optimization enables lithium to form stable alloys (such as Li-Ag alloys with γ1-phase and β-Li phase) that maintain structural stability while achieving high specific capacity, resolving the contradiction between energy density and structural stability.
3Quantity of substance
If silver content in negative active material layer is increased, then discharge capacity improves, but manufacturing precision requirements increase
Solution Approach 1:
The patent defines a broad but controlled parameter range for silver content (10-100 wt%) and amount per unit area (0.05-5 mg/cm2). This parameter specification provides manufacturing flexibility while ensuring performance, allowing manufacturers to achieve high discharge capacity without requiring extreme precision, thus resolving the contradiction between discharge capacity and manufacturing precision requirements.
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 discharge capacity and energy density of the battery while maintaining structural integrity without the need for excessive external pressure, improving the battery's performance and longevity.
Implementation Method 1
the negative active material layer comprises silver (Ag)... which is capable of forming an alloy or a compound with lithium
Data Source
AI summary
An all-solid lithium secondary battery includes: a positive active material layer; a solid electrolyte layer; and a negative active material layer, which is capable of forming an alloy or a compound with lithium, wherein the solid electrolyte layer is between the positive active material layer and the negative active material layer, and wherein the negative active material layer comprises silver (Ag).