Solid-State Battery Anode Composition for High-Rate Silicon Capacity

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Solution Overview

Problem

Existing lithium-ion batteries using silicon as a negative electrode material face challenges in achieving both high capacity and good discharge rate characteristics.

Innovation Solution

The battery design incorporates a positive electrode with a metal oxide containing lithium and a negative electrode with a negative electrode active material layer made of silicon that has lithium pre-stored therein, with an atomic ratio of lithium to silicon in a fully charged state of less than or equal to 3.5.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If silicon is used as a negative electrode active material to increase capacity, then the energy storage capacity is improved, but the discharge rate characteristics deteriorate due to poor electron conductivity

Engineering Contradiction:
Improvelithium storage capacityVSAvoiddischarge rate
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

Lithium is pre-stored in the silicon negative electrode material before battery operation. This preliminary action of incorporating lithium into the silicon structure ahead of time creates a lithium-silicon alloy that inherently possesses better electron conductivity, thereby resolving the discharge rate problem while maintaining high capacity

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the compositional parameter of the negative electrode by controlling the atomic ratio of lithium to silicon to be less than or equal to 3.5 in the fully charged state. This parameter optimization ensures sufficient electron conductivity for good discharge rate characteristics while preserving the high capacity advantage of silicon

Inventive Principle:
Principle #35Parameter changes

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 electron conductivity of the silicon negative electrode, thereby improving the discharge rate characteristics of the battery.

Implementation Method 1

the silicon having electron conductivity and also having ion conductivity

Methodology Applied
Scientific EffectElectron conduction: Conduction (electrical)

Implementation Method 2

the silicon having electron conductivity and also having ion conductivity

Methodology Applied
Scientific EffectIon conduction: Conduction (electrical)

Data Source

PatentUS20250046802A1battery
Publication Date: 2025.02.06 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • US20250046802A1 patent drawing
  • US20250046802A1 patent drawing

AI summary

The battery of the present disclosure includes: a positive electrode; a negative electrode; and a solid electrolyte layer located between the positive electrode and the negative electrode. The positive electrode contains, as a positive electrode active material, a metal oxide containing lithium, and the negative electrode includes a negative electrode current collector and a negative electrode active material layer located between the negative electrode current collector and the solid electrolyte layer. The negative electrode active material layer contains, as a negative electrode active material, silicon with lithium pre-stored therein. The atomic ratio of lithium to silicon in the negative electrode active material layer in a fully charged state is less than or equal to 3.5.