Mixed-Coating Battery Pack Layout for Energy Density and Power

Solution Overview

Problem

Conventional lithium-ion batteries face a trade-off between high energy density and high output characteristics, making it difficult to achieve both simultaneously when used in vehicles.

Innovation Solution

An energy storage device comprising alternating layers of thin-coated and thick-coated cells with specific active material thicknesses, controlled by an energy storage control device to manage power supply and charging based on vehicle state information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the thickness of the active material applied to the current collector is increased, then energy density is improved, but output characteristics deteriorate

Engineering Contradiction:

Improveenergy densityVSAvoidoutput characteristics

Core Design Contradiction:

Quantity of substanceVSPower

Solution Approach 1:

The battery pack is segmented into multiple battery modules, each containing battery cells with different active material thicknesses. This segmentation allows the system to combine cells with high energy density (thicker active material) and cells with high output characteristics (thinner active material) to achieve both high energy density and high output characteristics at the battery pack level.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different battery cells within the same battery pack have different local qualities in terms of active material thickness. Some cells are designed with thicker active material for high energy density, while others have thinner active material for high output characteristics. This local quality differentiation enables the overall system to achieve both high energy density and high output characteristics simultaneously.

Inventive Principle:

Principle #3Local quality

2Power

If the thickness of the active material applied to the current collector is decreased, then output characteristics are improved, but energy density deteriorates

Engineering Contradiction:

Improveoutput characteristicsVSAvoidenergy density

Core Design Contradiction:

PowerVSQuantity of substance

Solution Approach 1:

The battery pack is segmented into multiple battery modules, each containing battery cells with different active material thicknesses. This segmentation allows the system to combine cells with high energy density (thicker active material) and cells with high output characteristics (thinner active material) to achieve both high energy density and high output characteristics at the battery pack level.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different battery cells within the same battery pack have different local qualities in terms of active material thickness. Some cells are designed with thicker active material for high energy density, while others have thinner active material for high output characteristics. This local quality differentiation enables the overall system to achieve both high energy density and high output characteristics simultaneously.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS20260014879A1Energy storage device and energy storage system

Publication Date: 2026.01.15 ISUZU MOTORS LTD

AI summary

An energy storage device mounted in a moving body, the energy storage device including a plurality of thin-coated cells to which first active materials having thicknesses within a first range are applied between a current collector and a separator, and a plurality of thick-coated cells to which second active materials having thicknesses within a second range whose lower limit value is greater than an upper limit value of the first range, are applied between the current collector and the separator. The thin-coated cells and the thick-coated cells are alternately arranged at predetermined intervals.