Hybrid Battery Cell Absorbing Overcharge via Aqueous Decomposition

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Solution Overview

Problem

Conventional storage batteries face issues such as high cost, weight, and safety concerns due to the need for protective circuits and switches in lithium-ion batteries, while lead-acid batteries have low energy density and high weight, making them unsuitable for widespread use in electric vehicles and power storage systems.

Innovation Solution

A hybrid storage battery system combining lithium-ion batteries with lead-acid batteries, where the batteries are connected in series and parallel to share charging and discharging voltages, with a lead-acid battery absorbing overcharging energy to prevent lithium-ion battery overcharge, eliminating the need for protective circuits and switches, and allowing for detachable cassette modules for easy replacement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If lithium-ion batteries are used for high energy density and light weight, then energy density and weight are improved, but cost increases due to expensive electrode materials and protective circuits

Engineering Contradiction:
Improveenergy densityVSAvoidcost
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent combines lithium-ion batteries and lead-acid batteries into a hybrid storage system. The lithium-ion battery provides high energy density for extended range, while the lead-acid battery provides low-cost capacity for basic power needs and regenerative braking energy recovery, reducing overall system cost while maintaining energy density benefits.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent segments the battery functions by dividing the storage system into two parts: lithium-ion battery for high-energy applications and lead-acid battery for cost-sensitive applications. This segmentation allows each battery type to operate in its optimal performance range while reducing the need for expensive protective circuits in the lithium-ion portion.

Inventive Principle:
Principle #1Segmentation

2Weight of moving object

If lithium-ion batteries are used for high energy density, then weight is reduced, but cost increases due to the need for protective circuits and switches

Engineering Contradiction:
ImproveweightVSAvoidcost
Core Design Contradiction:
Weight of moving objectVSDevice complexity

Solution Approach 1:

The hybrid system merges lithium-ion and lead-acid batteries, allowing the lead-acid battery to handle functions that would require expensive protective circuits for lithium-ion batteries alone. The lead-acid battery's inherent tolerance to overcharge and overdischarge reduces the need for complex protection systems.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent employs lead-acid batteries as a cost-effective component in the hybrid system. Lead-acid batteries are cheaper and can be replaced more easily than lithium-ion batteries, providing an economical solution for energy recovery and basic power storage without requiring expensive protective infrastructure.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Device complexity

If lead-acid batteries are used for low cost, then cost is reduced, but weight increases due to low energy density

Engineering Contradiction:
ImprovecostVSAvoidweight
Core Design Contradiction:
Device complexityVSWeight of moving object

Solution Approach 1:

The patent merges lead-acid and lithium-ion batteries in a hybrid configuration where the lithium-ion battery's high energy density compensates for the lead-acid battery's weight. This combination allows the system to use cheaper lead-acid batteries for basic functions while adding only the necessary lithium-ion capacity to reduce overall weight compared to a pure lead-acid system.

Inventive Principle:
Principle #5Merging (Combining)

4Use of energy by moving object

If lithium-ion batteries are used for high energy density, then energy storage capacity is improved, but reliability decreases due to susceptibility to overcharge and overdischarge

Engineering Contradiction:
Improveenergy storage capacityVSAvoidreliability
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The lead-acid battery acts as an intermediary protective element in the hybrid system. Its inherent chemical stability and tolerance to voltage extremes protect the lithium-ion battery from overcharge and overdischarge conditions, enhancing overall system reliability while maintaining high energy storage capacity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The hybrid configuration provides beforehand cushioning by using the lead-acid battery's robust chemistry to absorb voltage extremes and protect the lithium-ion battery from damaging conditions. This protective arrangement is built into the system architecture from the beginning, preventing reliability issues before they occur.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 hybrid battery system reduces costs, improves power performance, and extends the life of lithium-ion batteries by using lead-acid batteries to absorb overcharge energy, enabling efficient energy storage and supply for electric vehicles and emergency power applications.

Implementation Method 1

the aqueous solution based battery is configured to carry out a decomposition reaction of the aqueous electrolyte to absorb the overcharging energy so that a charging voltage of the combined type battery is suppressed to the final charging voltage of the lead-acid battery

Methodology Applied
Scientific EffectDecomposition reaction: Decomposition (biological)

Implementation Method 2

a first battery string comprising a plurality of combined type batteries connected in series to each other, wherein: the combined type batteries are designed to have average discharging voltages approximate to each other so as to be capable of driving a load in parallel

Methodology Applied
Scientific EffectElectrical energy storage: Battery (electricity)

Data Source

PatentEP2768071B1Hybrid storage cell, vehicle and power storage unit employing same, smart grid vehicle system employing vehicle, and power supply network system employing power storage unit
Publication Date: 2017.04.05 CONNEXX SYST
  • EP2768071B1 patent drawingFigure 1~2
  • EP2768071B1 patent drawingFigure 3~4
  • EP2768071B1 patent drawingFigure 5

AI summary

Provided is a hybrid storage cell that can prevent overcharge, despite lacking an expensive protection switch or other device adapted to deal with high current or high voltage, in order to proactively prevent rupture or ignition of lithium ion storage cells or other organic solution storage cells in the event of unforeseen overcharging. The cell comprises a plurality of series-connected virtual cells (32) of parallel-connected organic solution storage cells (24A) and aqueous solution storage cells (26A), the organic solution storage cells and the aqueous solution storage cells having closely approximating average discharge voltages. The overcharge threshold voltage of the organic solution storage cells is designed to be higher than the final discharge voltage of the aqueous solution storage cells, and the final discharge voltage of the organic solution storage cells to be lower than the final discharge voltage of the aqueous solution storage cells. In the event that the organic solution storage cells of a virtual cell are exposed to overcharge energy that could lead to overcharge, the energy is absorbed by a hydrogen-generating reaction of the aqueous solution storage cells, holding the discharge voltage of the virtual cell to the final discharge voltage of the aqueous solution storage cells, and preventing the organic solution storage cells from reaching the overcharge threshold voltage.