Single-cell Battery Current Interruption Device for Overcharge Protection
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Solution Overview
Problem
Existing battery management systems fail to prevent overcharging in power batteries, leading to potential battery swelling and explosions due to voltage and current sampling failures, particularly in ternary systems where software failures or communication issues between charging piles and battery managers can result in uncontrolled recharging.
Innovation Solution
A single-cell battery design incorporating a current interruption device with a conductive member and flipping member connected by a boss welded structure, which disconnects under air pressure to interrupt the charge/discharge circuit, preventing further overcharging and potential explosions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If the battery management system relies on software control and communication between charging pile and battery manager, then charge/discharge management can be implemented, but software failure or communication issues can result in uncontrolled recharging
Solution Approach 1:
The patent segments the safety control into two independent layers: electronic control (battery management system) and mechanical control (current interruption device). The flipping member provides a physically separate control path that does not depend on software or communication systems. This segmentation ensures that failures in the automated management system do not compromise overall safety.
Solution Approach 2:
The current interruption device provides beforehand cushioning by preparing a mechanical safety mechanism in advance that can immediately interrupt current flow when needed. The flipping member is pre-positioned to block the current path, and only needs to be triggered by temperature changes, providing a cushion of safety before overcharging can cause damage.
2Reliability
If a current interruption device uses a flipping member to disconnect the circuit under air pressure, then overcharging can be prevented, but the device complexity increases
Solution Approach 1:
The patent uses pneumatic pressure from the battery's internal gas generation during overcharging to actuate the flipping member. The air pressure generated by battery swelling directly pushes the flipping member to disconnect the circuit, eliminating the need for external sensors, actuators, or power sources. This pneumatic mechanism simplifies the device by using the battery's own overcharge symptoms as the actuating force.
Solution Approach 2:
The flipping member mechanism is self-actuating through temperature-induced material properties. The flipping member is made of a material whose mechanical properties change with temperature, allowing it to automatically flip and disconnect the circuit when the battery temperature rises due to overcharging. This self-service mechanism eliminates complex control systems while maintaining reliable protection.
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 current interruption device effectively prevents battery overcharging by disconnecting the charge/discharge circuit under emergency conditions, enhancing safety by ensuring timely interruption of current flow and maintaining stability during high current transmission.
Implementation Method 1
The flipping member and the conductive member can be electrically disconnected from each other under action of air pressure
Implementation Method 2
The flipping member and the conductive member are connected to each other by using a boss welded structure
Implementation Method 3
The battery post is mounted in a ceramic ring tightly connected to the cover plate and is insulated from the outer periphery of the flipping member by using the ceramic ring
Data Source
AI summary
The present disclosure is directed to a single-cell battery, a battery module, a power battery, and an electric vehicle. The single-cell battery includes a case, a battery cell accommodated in the case, an electrode terminal electrically connected to the battery cell, and a cover plate for sealing the case. The electrode terminal is disposed on the cover plate. The electrode terminal includes a battery post passing through the cover plate and electrically connected to the battery cell. The single-cell battery further includes a current interruption device mounted on the battery post. The current interruption device is in communication with gas inside the case. The current interruption device has a conductive member and a flipping member connected to the conductive member for mutual electrical connection. The flipping member and the conductive member are electrically disconnected from each other under action of air pressure. The conductive member is connected to the battery post for mutual electrical connection.