Lithium-Magnesium Alloy Anode for Solid-State Battery Efficiency
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Solution Overview
Problem
Conventional all-solid-state lithium secondary batteries suffer from low charge-discharge efficiency due to irreversible lithium metal precipitation during charge-discharge cycles, which blocks ion conducting paths and prevents uniform dissolution of lithium metal.
Innovation Solution
Incorporating a single p-phase alloy of lithium and magnesium as the anode active material, with a lithium content of 81.80 atomic % or more and 99.97 atomic % or less, to facilitate uniform diffusion of lithium ions and enhance charge-discharge efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a conventional all-solid-state battery structure with lithium metal anode is used, then the battery can achieve high output voltage due to lithium's large ionization tendency, but the charge-discharge efficiency becomes low due to irreversible lithium metal precipitation blocking ion conducting paths
Solution Approach 1:
The patent uses a composite anode structure consisting of a current collector, a solid electrolyte layer, and a lithium metal layer. This composite structure allows the battery to maintain high output voltage from lithium metal while the solid electrolyte layer prevents irreversible precipitation, thereby resolving the contradiction between high power and reliable charge-discharge efficiency
Solution Approach 2:
The solid electrolyte layer acts as an intermediary between the current collector and the lithium metal layer. It mediates the ion transport process, allowing lithium ions to move freely during charge-discharge cycles while preventing the formation of blocking precipitation layers, thus maintaining both high voltage and high efficiency
2Quantity of substance
If lithium metal is used as the anode active material, then high energy density can be achieved, but uniform dissolution of lithium metal is prevented due to irreversible precipitation during charge-discharge cycles
Solution Approach 1:
The solid electrolyte layer serves as a mediator that enables uniform dissolution of lithium metal by providing a controlled interface for ion exchange. It prevents localized precipitation while maintaining high lithium content, thus achieving both high energy density and stable compositional uniformity
Solution Approach 2:
The patent controls the thickness and composition parameters of the solid electrolyte layer to optimize lithium ion transport. By adjusting these parameters, the system achieves uniform lithium dissolution throughout the anode while maintaining high energy density from the lithium metal content
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 a lithium-magnesium alloy anode layer ensures high charge-discharge efficiency by allowing uniform lithium ion diffusion, reducing resistance, and increasing energy density, while also suppressing the formation of resistance layers that can cause short circuits.
Implementation Method 1
facilitate uniform diffusion of lithium ions
Implementation Method 2
solid electrolyte layer disposed between the cathode layer and the anode layer
Data Source
AI summary
Provided is an all-solid-state battery with high charge-discharge efficiency, and a method for producing the all-solid-state battery. Disclosed is an all-solid-state battery, wherein a lithium metal precipitation-dissolution reaction is used as an anode reaction; wherein the all-solid-state battery comprises a cathode comprising a cathode layer, an anode comprising an anode current collector and an anode layer, and a solid electrolyte layer disposed between the cathode layer and the anode layer; wherein the anode layer contains, as an anode active material, a single β-phase alloy of a lithium metal and a magnesium metal; and wherein a percentage of the lithium element in the alloy is 81.80 atomic % or more and 99.97 atomic % or less when the all-solid-state battery is fully charged.