Stepped Battery Pack Housing With Stacked Cold Plates

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Solution Overview

Problem

Current battery packs face challenges in increasing the number of battery cells due to limited installation space, leading to large volume and practical difficulties, especially when stacking multiple battery packs.

Innovation Solution

A battery pack housing design featuring a tray with side beams and steps for multiple layers of cold plates, where each layer supports a layer of battery cells, with varying sizes and fastening methods to optimize space utilization and heat management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If multiple battery packs are stacked to increase the number of battery cells, then the battery cell capacity increases, but the overall volume becomes large and difficult to use

Engineering Contradiction:
Improvenumber of battery cellsVSAvoidbattery pack volume
Core Design Contradiction:
Quantity of substanceVSVolume of moving object

Solution Approach 1:

The patent transitions from a single-layer horizontal arrangement to a multi-layer vertical stacking arrangement. Multiple cold plates are stacked in the vertical direction, with each cold plate supporting a layer of battery cells. This dimensional change allows the battery pack to accommodate more battery cells without proportionally increasing the horizontal footprint, thereby reducing the overall volume while increasing capacity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent implements a nested structure where multiple cold plates and battery cell layers are stacked within a single battery pack housing. Each cold plate with its corresponding battery cells is nested within the same structural envelope, creating a compact multi-layer configuration that maximizes space utilization and reduces the external dimensions of the battery pack.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Quantity of substance

If the battery cell capacity is increased to extend driving range, then the energy storage increases, but the installation space requirement increases

Engineering Contradiction:
Improvebattery cell capacityVSAvoidinstallation space
Core Design Contradiction:
Quantity of substanceVSArea of stationary object

Solution Approach 1:

The patent utilizes the vertical dimension by stacking multiple cold plates and battery cell layers one above another. This vertical arrangement allows the battery pack to achieve high capacity without expanding the horizontal installation area, effectively solving the space constraint problem while increasing energy storage capability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The battery pack is segmented into multiple independent layers, each consisting of a cold plate and battery cells. This segmentation allows for efficient space utilization and enables the system to achieve high capacity through vertical stacking rather than horizontal expansion, thereby reducing the required installation area.

Inventive Principle:
Principle #1Segmentation

3Quantity of substance

If the number of battery cells is increased through better integration, then the capacity increases, but the structural complexity increases

Engineering Contradiction:
Improvebattery cell integrationVSAvoidstructural complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The cold plate structure serves multiple functions: it acts as a thermal management component for cooling battery cells, provides structural support for mounting battery cells, and serves as a modular unit that can be stacked to increase capacity. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in structural complexity while achieving better integration.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the thermal management function and structural support function into a single cold plate component. By combining these functions, the design avoids adding separate cooling systems and support structures, thus increasing battery cell integration without proportionally increasing structural complexity.

Inventive Principle:
Principle #5Merging (Combining)

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 design results in a compact, efficient battery pack structure that is easy to use, allowing for increased battery cell capacity and improved heat management, enhancing the battery pack's reliability and stability.

Implementation Method 1

n layers of cold plates... each layer of cold plate is used for arrangement of a layer of battery cells

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 2

the cold plate is fastened to steps of the first side beam and the second side beam by welding with welding rods

Methodology Applied
Scientific EffectWelding: Welding

Implementation Method 3

the cold plate is fastened to steps of the first side beam and the second side beam by bonding with an adhesive tape

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP4685957A1Battery pack housing, battery pack, and electric device
Publication Date: 2026.01.28 BYD CO LTD
  • EP4685957A1 patent drawingFigure 1
  • EP4685957A1 patent drawingFigure 2~3
  • EP4685957A1 patent drawingFigure 4~5

AI summary

An electrical device includes a battery pack. The battery pack includes a battery pack housing. The battery pack housing includes a tray and n layers of cold plates, wherein the tray includes a first side beam and a second side beam opposite to each other, m steps are separately disposed on either opposite side of the first side beam and the second side beam, and m≥3; two opposite ends of the n layers of cold plates are disposed on corresponding steps of the first side beam and the second side beam, each layer of cold plate corresponds to one step, each layer of cold plate is used for arrangement of a layer of battery cells, 2≤n≤m, and the m steps and the n layers of cold plates are numbered in an ascending order from the bottom to the top of the first side beam; and in a direction from the first side beam to the second side beam, a size of an (n-1)th layer of cold plate is smaller than a size of the nth layer of cold plate.