EnerSys has filed a patent for a fire safety arrangement for metal ion batteries, specifically lithium ion batteries. The arrangement includes a safety valve or vent to release gas build-up and a fabric envelope to contain sparks, reducing the risk of fire or explosion. GlobalData’s report on EnerSys gives a 360-degree view of the company including its patenting strategy. Buy the report here.

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According to GlobalData's company profile on EnerSys, corrosion resistant battery packaging was a key innovation area identified from patents. EnerSys's grant share as of June 2023 was 1%. Grant share is based on the ratio of number of grants to total number of patents.

Fire safety arrangement for a metal ion battery

Source: United States Patent and Trademark Office (USPTO). Credit: EnerSys

A recently filed patent (Publication Number: US20230198082A1) describes a metal ion battery cell with unique safety features. The battery cell includes multiple electrodes and an electrolyte enclosed within a housing. The housing is equipped with a safety valve or vent that allows any gas build-up within the housing to be released outside. Additionally, the housing is surrounded by a fabric envelope, which serves to contain any sparks generated by the battery.

The patent claims specify that the metal ion battery cell is a lithium ion battery cell, and it can be either prismatic or cylindrical in shape. The fabric envelope fully surrounds the housing, minimizing the presence of oxygen between the envelope and the housing. The fabric envelope is designed to be gas permeable, allowing gas to escape from within the envelope when the pressure inside is higher than outside. Conversely, when there is no pressure difference, little to no gas passes through the fabric envelope.

The safety valve in the housing is a one-way valve that opens when the pressure within the lithium ion battery cell reaches 0.9 MPa, or within a range of 0.9 MPa±0.2 MPa. The material of the fabric envelope allows gas to pass through when the pressure within the envelope is at the specified range. The fabric envelope is also elastically deformable, providing flexibility to accommodate changes in pressure.

The fabric envelope is made from a heat-resistant material and can comprise a felt material needled to or between one or more woven fabrics. It includes at least one connection port that allows wires to pass through and connect to the terminals of the lithium ion battery cell.

The patent also describes the use of these metal ion battery cells in a power module and a battery pack. In both cases, multiple metal ion battery cells are enclosed within a housing equipped with a safety valve or vent and surrounded by a fabric envelope to contain sparks generated by the battery cells.

Overall, this patent presents a metal ion battery cell design that prioritizes safety by incorporating a fabric envelope to contain sparks and a safety valve to release any gas build-up. The design is versatile, accommodating different shapes of lithium ion battery cells, and the fabric envelope allows for gas permeability and elastic deformability.

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GlobalData, the leading provider of industry intelligence, provided the underlying data, research, and analysis used to produce this article.

GlobalData Patent Analytics tracks bibliographic data, legal events data, point in time patent ownerships, and backward and forward citations from global patenting offices. Textual analysis and official patent classifications are used to group patents into key thematic areas and link them to specific companies