Cell-to-Body Battery Pack Structure for Lighter EV Floors

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing electric vehicle designs face challenges in weight reduction and energy density due to separate floor panels and cell pack cases, leading to reduced endurance mileage and increased structural weight.

Innovation Solution

A cell-to-body structure where the top of the power cell pack case serves as both part of the cell pack and the vehicle's floor panel, integrated with a cross beam connecting to the vehicle body, reducing structural redundancy and enhancing stability and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If separate floor panel and cell pack case are used, then structural strength is improved, but vehicle weight increases

Engineering Contradiction:
Improvestructural strengthVSAvoidvehicle weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent merges the floor panel and cell pack case into a single integrated structure where the cell pack case top surface serves dual functions as both the cell pack cover and the vehicle floor panel. This eliminates the need for a separate floor panel, reducing structural redundancy and vehicle weight while maintaining structural strength through the integrated design.

Inventive Principle:
Principle #5Merging (Combining)

2Stability of the object's composition

If separate floor panel and cell pack case are used, then structural stability is improved, but energy density decreases

Engineering Contradiction:
Improvestructural stabilityVSAvoidenergy density
Core Design Contradiction:
Stability of the object's compositionVSQuantity of substance

Solution Approach 1:

By integrating the floor panel function into the cell pack case structure, the patent eliminates redundant structural components, thereby increasing the space available for battery cells. This integration maintains structural stability through the cross beam and mounting portions while increasing energy density by maximizing the battery volume within the vehicle floor area.

Inventive Principle:
Principle #5Merging (Combining)

3Weight of moving object

If integrated cell pack case and floor panel are used, then vehicle weight is reduced, but manufacturing complexity increases

Engineering Contradiction:
Improvevehicle weightVSAvoidmanufacturing complexity
Core Design Contradiction:
Weight of moving objectVSEase of manufacture

Solution Approach 1:

The integrated structure is designed with modular segmentation, where the cell pack case includes distinct functional elements (mounting portions, cross beam, sealing structures) that can be manufactured separately and then assembled. This segmentation approach reduces manufacturing complexity compared to creating a fully integrated monolithic structure, while still achieving the weight reduction benefits of integration.

Inventive Principle:
Principle #1Segmentation

4Device complexity

If integrated cell pack case and floor panel are used, then structural redundancy is reduced, but connection complexity increases

Engineering Contradiction:
Improvestructural redundancyVSAvoidconnection complexity
Core Design Contradiction:
Device complexityVSEase of manufacture

Solution Approach 1:

The cell pack case is designed with universal mounting portions that serve multiple functions: structural connection to the vehicle body, sealing interface, and battery assembly mounting. The cross beam structure provides both structural support and mounting functionality. This multi-functionality reduces the need for separate connection components, thereby reducing connection complexity despite the integrated design.

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

Data Source

PatentEP4279304A1Cell-to-body structure and vehicle
Publication Date: 2023.11.22 XIAOMI EV TECH CO LTD
  • EP4279304A1 patent drawingFigure 1
  • EP4279304A1 patent drawingFigure 2
  • EP4279304A1 patent drawingFigure 3

AI summary

The disclosure relates to a cell-to-body structure and a vehicle, belongs to the field of vehicles. The cell-to-body structure includes a vehicle body (1) and a power cell pack (2), the vehicle body (1) includes two sill beams (11) which being arranged in a spaced manner in a left-right direction of a vehicle, a cell pack mounting portion is on each of the sill beams (11); the power cell pack (2) includes a cell pack case (21) which including a case body (211) and a cross beam (24), the case body (211) being connected to the cell pack mounting portion, the cross beam (24) extending in the left-right direction, being located between the two sill beams (11) and integrated at a top of the case body (211) and connected to the vehicle body (1), the top of the case body (211) being used as a floor panel of the vehicle.