Battery Electrolyte Filling via Bottom-Up Inversion

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Solution Overview

Problem

Existing methods for filling accumulators with liquid electrolyte often result in gas inclusions and staining on the separator material due to trapped gases, which are undesirable and affect the performance of the accumulator.

Innovation Solution

The method involves filling the accumulator through a filling opening arranged at the top or above the center of the housing, ensuring that the uppermost point of the battery electrodes remains free of liquid electrolyte during the filling process, allowing gases to escape and preventing the formation of a 'lake' on the electrodes, thereby reducing gas inclusions and ensuring homogeneous filling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the accumulator is filled rapidly with liquid electrolyte through vacuum suction, then the filling speed is high and productivity is improved, but gas accumulations are trapped between the battery electrodes and separator material

Engineering Contradiction:
Improvefilling speedVSAvoidgas inclusions
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

Instead of filling from the top where gas gets trapped, the patent inverts the filling approach by supplying electrolyte from below the battery electrodes. The filling opening is positioned at the bottom of the housing, and electrolyte is introduced upward, allowing gas to escape naturally toward the top rather than being trapped between electrodes.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the spatial dimension of filling by moving the filling opening from the top surface to the bottom surface of the housing. This dimensional inversion transforms the filling trajectory from top-down to bottom-up, fundamentally changing how gas and electrolyte interact during the filling process.

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

2Manufacturing precision

If the uppermost point of battery electrodes is completely covered with liquid electrolyte during filling, then complete wetting is achieved, but gas escape paths are blocked and staining occurs on separator material

Engineering Contradiction:
Improvewetting homogeneityVSAvoidseparator staining
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent inverts the filling direction so that electrolyte rises from below rather than pouring from above. This ensures the uppermost points of electrodes remain the last to be wetted, naturally maintaining gas escape paths open while achieving complete wetting as the electrolyte level gradually rises.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent establishes preliminary gas escape paths by positioning the filling opening at the bottom, creating a predetermined upward flow path that naturally allows gas to escape before electrolyte reaches the uppermost electrode points. This preliminary arrangement prevents staining before it can occur.

Inventive Principle:
Principle #10Preliminary action

3Object-generated harmful factors

If vacuum evacuation is performed before filling, then gas inclusions are reduced, but the filling process must be interrupted to allow gas escape

Engineering Contradiction:
Improvegas inclusionsVSAvoidfilling process interruption
Core Design Contradiction:
Object-generated harmful factorsVSLoss of time

Solution Approach 1:

By inverting the filling direction to bottom-up, the patent eliminates the need for vacuum evacuation and process interruptions. Gas naturally escapes upward during continuous filling, making the preliminary vacuum step and intermediate pauses unnecessary.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The inverted filling method enables continuous electrolyte supply without interruptions. The useful action of filling proceeds continuously from bottom to top, with gas escaping naturally throughout the process, eliminating the need to pause for gas venting or perform separate vacuum steps.

Inventive Principle:
Principle #20Continuity of useful action

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 approach allows for continuous, quick filling without interrupting the process, reducing gas inclusions and ensuring a homogeneous wetting of the battery electrodes, leading to improved accumulator performance and reduced staining on the separator material.

Implementation Method 1

liquid electrolyte is supplied through the at least one filling opening in such a way that at no time during the filling process of the liquid electrolyte is the uppermost point of the battery electrodes in relation to the effective direction of gravity completely covered with the liquid electrolyte

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 2

The interior of the housing 1 is evacuated by a vacuum. A predetermined amount of liquid electrolyte 2 is sucked into the housing 1 through the filling opening 5 by the vacuum.

Methodology Applied
Scientific EffectVacuum: Vacuum

Implementation Method 3

Particularly in the case of very fine-fibered separator material, the escape of the gas is made even more difficult by capillary effects.

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Data Source

PatentEP2745339B1Method for producing a battery filled with a liquid electrolyte and battery
Publication Date: 2018.03.14 JOHNSON CONTROLS AUTOBATTERIE GMBH & CO KGAA
  • EP2745339B1 patent drawingFigure 1~2
  • EP2745339B1 patent drawingFigure 3~4
  • EP2745339B1 patent drawingFigure 5~6

AI summary

The invention relates to a method for producing a battery (10) filled with a liquid electrolyte (2, 11), wherein the battery (10) comprises a housing (1) having a top side (3) lying at the top in the normal operation of the battery (10) and a bottom side (4) opposite the top side (3), wherein battery electrodes (6) are arranged in the housing (1) and the housing (1) has at least one filling opening (5) for the liquid electrolyte (2, 11), which filling opening is arranged on the top side (3) of the housing (1) or at least above the center of the housing (1), characterized in that liquid electrolyte (2, 11) is fed through the at least one filling opening (5) in such a way that the topmost point (16) of the battery electrodes (6) with respect to the direction of action of gravity is not completely covered with the liquid electrolyte (2, 11) at any time during the process of filling the battery with liquid electrolyte (2, 11). The invention further relates to a filling vessel designed for performing the method, to a machine, and to a battery.