Alkaline Dry Battery PEG Additive for Short-Circuit Heat Suppression
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Solution Overview
Problem
Alkaline dry batteries face a challenge in suppressing temperature increases during external short circuits, which affects safety and performance.
Innovation Solution
Incorporating a polyethylene glycol compound with a melting point of 46° C. or more in the gaps between the negative electrode and the sealing unit or the bottom portion of the battery case, which absorbs heat generated during a short circuit, thereby reducing temperature increases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a polyethylene glycol with low molecular weight (190-7000) is used to suppress hydrogen generation reaction, then hydrogen generation is suppressed, but temperature increase during external short circuit cannot be effectively controlled
Solution Approach 1:
The patent changes the key parameter of the polyethylene glycol from low molecular weight (190-7000) to high molecular weight (7000-100,000). This parameter change fundamentally alters the material's behavior: high molecular weight PEG has higher melting point and better heat absorption capacity, enabling it to suppress temperature increase during short circuits while still preventing hydrogen generation.
Solution Approach 2:
The patent utilizes the phase transition (melting) of high molecular weight polyethylene glycol to absorb heat during external short circuits. The PEG transitions from solid to liquid state at its melting point, absorbing latent heat and thereby suppressing temperature increase. This phase transition mechanism is specifically effective for thermal management during abnormal conditions.
2Ease of manufacture
If the battery structure is simplified without additives, then manufacturing is easier, but temperature increase during external short circuit occurs
Solution Approach 1:
The patent uses polyethylene glycol as a sacrificial material that absorbs heat during short circuits through its phase transition. The PEG is consumed in the process of absorbing heat (melting), but it is a low-cost material that provides effective thermal management without requiring complex or expensive safety mechanisms.
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
Effectively suppresses temperature rises during external short circuits, enhancing safety and maintaining discharge performance by positioning the additive near the electrode terminal areas.
Implementation Method 1
an additive is packed in a gap between the negative electrode and the sealing unit and/or a gap between the negative electrode and the bottom portion, and the additive contains a polyethylene glycol compound that has a melting point of 46° C. or more
Implementation Method 2
the additive contains a polyethylene glycol compound that has a melting point of 46° C. or more
Data Source
AI summary
An alkaline dry battery includes: a bottomed cylindrical case including: a bottom portion having a positive electrode terminal portion; and a cylindrical side portion; a hollow cylindrical positive electrode in internal contact with the case; a negative electrode that is packed in a hollow portion of the positive electrode and contains a negative electrode active material containing zinc; a separator interposed between the positive electrode and the negative electrode; an alkaline electrolyte solution; and a sealing unit. The alkaline electrolyte solution is contained in the positive electrode, the negative electrode, and the separator. The sealing unit has a negative electrode terminal portion, and covers an opening of the case. An additive is packed in a gap between the negative electrode and the sealing unit and/or a gap between the negative electrode and the bottom portion. The additive contains a polyethylene glycol compound with a melting point of 46° C. or more.