Battery Safety Device with Electric Field Gas Generation
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Solution Overview
Problem
Current lithium-ion batteries face safety hazards due to overcharging and overheating, which are exacerbated by the use of lithium carbonate as an overcharge additive, leading to reduced energy density, increased internal resistance, and the risk of metallic foreign bodies.
Innovation Solution
A lithium-ion battery design that incorporates a safety device with a first and second electrode arranged to form an electric field, where a gas generating material is placed within the electric field to produce an inert gas upon overcharging, which increases the gas generation rate and escapes directly into the battery, thereby enhancing safety and reducing the need for doping lithium carbonate in the electrode plates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lithium carbonate is doped in electrode plates to prevent overcharging, then safety protection is provided, but energy density is reduced and internal resistance increases
Solution Approach 1:
The invention separates the safety function from the electrode structure by placing gas generating material in a dedicated safety device rather than doping it into electrode plates. This segmentation allows the electrode plates to maintain their original composition and performance characteristics while the separate safety device provides overcharge protection through gas generation and circuit interruption.
Solution Approach 2:
The invention introduces a current cut-off device as an intermediary component between the gas generating material and the circuit. This intermediary translates the chemical reaction (gas generation) into an electrical safety function (circuit interruption), enabling the safety mechanism to operate without directly affecting electrode composition or performance.
2Reliability
If lithium carbonate is doped in electrode plates to prevent overcharging, then safety protection is provided, but the risk of introducing metal foreign bodies increases
Solution Approach 1:
The invention extracts the gas generating material from the electrode structure and places it in a separate safety device. This extraction eliminates the risk of metal foreign bodies entering the electrode system during doping processes, while the safety function is maintained through the isolated safety device that generates gas and triggers circuit interruption.
3Reliability
If lithium carbonate is dispersed in electrode plates to prevent overcharging, then safety protection is provided, but operation efficiency is reduced due to high melting point and slow response
Solution Approach 1:
The invention replaces the thermal-based safety mechanism (relying on high melting point of lithium carbonate) with an electrical field-based mechanism. The gas generating material is positioned in an electric field between electrodes, allowing it to respond to overcharge conditions through electrical field effects rather than waiting for thermal accumulation, thereby significantly improving response speed and operation efficiency.
4Reliability
If current cut-off device is used to interrupt circuit under high gas pressure, then temperature rise is prevented, but device complexity increases
Solution Approach 1:
The invention merges the gas generation function and circuit interruption function into a single integrated safety device. The gas generating material and current cut-off device work together as a unified safety mechanism, eliminating the need for separate safety components and reducing overall device complexity while maintaining effective temperature control.
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 proposed solution effectively increases the reaction rate and gas generation during overcharging, enhancing the safety of the battery by preventing overheating and reducing the negative impacts on energy density and internal resistance, while minimizing the risk of introducing metallic foreign bodies.
Implementation Method 1
a gas generating material, wherein the gas generating material is provided in the electric field and capable of generating an inert gas when a voltage in the electric field reaches or exceeds a predetermined threshold value
Implementation Method 2
the first electrode and the second electrode are arranged spaced apart from each other, and an electric field is formed between the first electrode and the second electrode
Implementation Method 3
a current cut-off device electrically connected between the cell and the electrical terminal and capable of causing a brake of circuit in response to a pressure difference between the inside of the battery and an external environment caused by the inert gas generated by the safety device
Data Source
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AI summary
The present invention provides a battery, comprising a case, a cell packaged in the case, an electrical terminal located at one end of the case and electrically connected to the cell, a safety device and a current cut-off device. The safety device comprises a first electrode and a second electrode arranged spaced apart from each other and respectively electrically connected to a positive electrode or a negative electrode. The first electrode and the second electrode are arranged spaced apart from each other and form an electric field, and a gas generating material capable of generating an inert gas when a voltage reaches or exceeds a threshold value is provided in the electric field. The current cut-off device is electrically connected between the cell and the electrical terminal and is capable of causing a brake of circuit in response to a pressure difference between the inside and the outside of the battery caused by the inert gas. According to the present invention, the safety device has a high gas generation rate, and the gas may escape directly into an internal space of the battery, thereby increasing a reaction rate. The energy density and the power density of electrode plates are increased, while the risk of introducing metallic foreign bodies can be reduced, with less negative impact on the design and the electrochemical performance of the cell.