US-20260128417-A1 - BATTERY TEMPERATURE MANAGEMENT

US20260128417A1US 20260128417 A1US20260128417 A1US 20260128417A1US-20260128417-A1

Abstract

A battery and thermal management system, which has a battery and a heat transfer arrangement. An electrical terminal extends from each of the cells in the battery, and adjacent pairs of terminals are electrically connected together. The heat transfer arrangement has an inlet channel, an outlet channel, and a plurality of heat transfer channels. The heat transfer channels are defined between respective inflow walls and outflow walls, and extend between the inlet channel and the outlet channel. There is a permeable barrier in each heat transfer channel which is slanted, so that it is positioned furthest from the inflow wall at a first end of the heat transfer channel, and closest to the inflow wall at a second end of the heat transfer channel. Each permeable barrier is in thermal contact with a connected pair of terminals along a length of the permeable barrier,

Inventors

Daniel Fahy
Jack Robert NICHOLAS
Tsun Holt Wong

Assignees

Qdot Technology Ltd

Dates

Publication Date: 20260507
Application Date: 20230928
Priority Date: 20220928

Claims (16)

1 . A battery and thermal management system comprising a battery and a heat transfer arrangement, the battery comprising a plurality of mutually adjacent cells, each of said cells comprising an electrical terminal extending therefrom, adjacent pairs of said terminals being electrically connected together to form a connected pair; the heat transfer arrangement comprising: an inlet channel, an outlet channel, and a plurality of heat transfer channels defined between respective inflow walls and outflow walls, wherein the heat transfer channels extend between the inlet channel and the outlet channel; each heat transfer channel further comprising a respective permeable barrier therein, the permeable barriers being slanted relative to the corresponding inflow and outflow walls so as to be positioned furthest from the inflow wall at a first end of the respective heat transfer channel proximate the inlet channel, and closest to the inflow wall at a second end of the respective heat transfer channel proximate the outlet channel; and, wherein each permeable barrier is in thermal contact with a respective connected pair of terminals along a length of the permeable barrier.
2 . The battery and thermal management system of claim 1 , further comprising a pumping system arranged to pump a heat transfer fluid through the heat transfer arrangement from the inlet channel to the outlet channel, through the heat transfer channels.
3 . The battery and thermal management system of claim 1 , wherein the heat transfer arrangement is arranged such that in use, substantially equal mass flows of a or the heat transfer fluid are distributed into each heat transfer channel.
4 . The battery and thermal management system of claim 1 , wherein the inlet channel comprises a cross-sectional area which varies between a maximum at a proximal end of the inlet channel and a minimum at a distal end of the inlet channel.
5 . The battery and thermal management system of claim 1 , wherein the outlet channel comprises a cross-sectional area which varies between a maximum at a proximal end of the outlet channel and a minimum at a distal end of the outlet channel.
6 . The battery and thermal management system of claim 1 , wherein at least one of the permeable barriers comprises a series of longitudinally spaced heat transfer features.
7 . The battery and thermal management system of claim 6 , wherein at least some of the heat transfer features comprise walls or protrusions, and a or the heat transfer fluid is made to flow through the space between adjacent protrusions.
8 . The battery and thermal management system of claim 6 , wherein at least some of the heat transfer features comprise holes.
9 . The battery and thermal management system of claim 1 , wherein the heat transfer channels are arranged such that in use, a heat transfer fluid comes into direct contact with a surface of the connected pairs of terminals.
10 . The battery and thermal management system of claim 9 , wherein the heat transfer fluid impinges substantially normally onto one or more of the terminal surfaces.
11 . The battery and thermal management system of claim 9 , wherein for each heat transfer channel, an electrical terminal of a connected pair forms a first wall of the heat transfer channel, and an electrical terminal of an adjacent connected pair forms a second wall of the heat transfer channel.
12 . The battery and thermal management system of claim 9 , wherein for each heat transfer channel, the first electrical terminal of a connected pair forms a first wall of the heat transfer channel and the second electrical terminal of the same connected pair forms a second wall of the heat transfer channel.
13 . The battery and thermal management system of claim 9 , wherein each connected pair of terminals extends through a base portion of the heat transfer arrangement such that the connected pair forms a portion of a base wall of each heat transfer channel.
14 . The battery and thermal management system of claim 1 , wherein the heat transfer arrangement comprises a base portion with an outer wall that the connected pairs of terminals do not extend through.
15 . The battery and thermal management system of claim 14 , wherein the outer wall of the base portion is shaped to fit over the connected pairs of terminals.
16 . The battery and thermal management system of claim 14 , wherein a thermally conductive gap-filling material is used to provide thermal contact between the connected pairs of terminals and the base portion.

Description

This invention relates to the thermal management of batteries, such as those used to power electric and hybrid-electric vehicles (EVs), which could include terrestrial vehicles, boats, underwater vehicles or airborne vehicles, all either manned or unmanned. They could also be used in other applications, including, but not limited to, stationary energy storage or portable energy storage. All forms of electric transport are becoming increasingly popular due to concerns over the environmental impacts of traditional fossil fuel powered engines, and the reduced environmental impact of electrically powered vehicles in comparison. Energy storage is also an increasingly important part of electricity infrastructure, on account of the intermittent nature of renewable energy sources. However, limitations to battery technology at present hinders further expansion of the use of batteries in the abovementioned applications. One such limitation is the need to control the temperature of the battery through heating or cooling. The desired operating temperature of the batteries can be more or less than the ambient air temperature. A battery which is too cold may compromise efficiency of its operation during use, and conversely charging and discharging cycles generate heat which degrades the performance of the battery over its lifetime. Furthermore, overheating can lead to fire or power failure. Cooling is therefore an integral safety feature for the prevention of overheating, and thermal management is an important factor in improving a battery's performance and lifetime. Pouch cells are commonly used for batteries in EVs. Pouch cells have a housing within which are a plurality of sub-cells, each composed of a negative electrical collector, an anode and cathode, separated by an ion-permeable electrode separation layer, and a positive electrical collector. An electrolyte surrounds the layers of the sub-cell. These sub-cells are layered to form a cell, with the multiple layers of electrical collectors coupled to electrically and thermally conductive electrical terminals, commonly described as tabs, which extend beyond the cell housing. Current methods of battery cooling in EVs rely on the interface between the layers of cells being cooled as this provides the largest surface area over which to cool. The Applicant has appreciated there are shortcomings associated with this method, in particular the temperature gradient this causes across the depth of the battery due to the poor thermal conductivity through the multiple layers within the sub cells and particularly the typically high contact resistance between respective layers. This leads to the hottest part of the battery (the centre) dictating the lifetime of the battery as a whole. Applying a tab cooling method, where coolant flows through channels between the “tabs” and carries heat away from the battery is a known solution used to partly address the uneven cooling which can occur across the depth of each cell. However, the Applicant has appreciated that the length of a cooling channel running between the tabs results in the temperature of the coolant fluid rising along its length. This results in non-uniform heat transfer away from the battery, and as a result, an undesirable temperature gradient along the length of each pouch cell. Temperature gradients across the cells can be lessened by increasing the flow rate of coolant. However, where driving the fluid actively, this requires greater power, or where encouraging airflow passively, this requires physically larger heat transfer features to sufficiently mitigate against temperature gradients. From a first aspect, the invention provides a battery and thermal management system arrangement comprising a battery and a heat transfer arrangement, the battery comprising a plurality of mutually adjacent cells, each of said cells comprising an electrical terminal extending therefrom, adjacent pairs of said terminals being electrically connected together to form a connected pair; the heat sink arrangement comprising: an inlet channel,an outlet channel, anda plurality of heat transfer channels defined between respective inflow walls and outflow walls, wherein the heat transfer channels extend between the inlet channel and the outlet channel; each heat transfer channel further comprising a respective permeable barrier therein, the permeable barriers being slanted relative to the corresponding inflow and outflow walls so as to be positioned furthest from the inflow wall at a first end of the respective heat transfer channel proximate the inlet channel, and closest to the inflow wall at a second end of the respective heat transfer channel proximate the outlet channel; and, wherein each permeable barrier is in thermal contact with a respective connected pair of terminals along a length of the permeable barrier. Thus it will be seen that, in accordance with the invention, slanted permeable barriers are positioned in each he