US-12627007-B2 - Battery configuration for reducing electromagnetic interference

US12627007B2US 12627007 B2US12627007 B2US 12627007B2US-12627007-B2

Abstract

The present document describes a battery configuration for reducing electromagnetic interference (EMI). The battery configuration includes a coin cell (e.g., stacking battery cell, button cell) with predefined external-tab configurations and a predefined internal-tab angle for reducing electromagnetic (EM) coupling. In particular, internal tabs are positioned to be separated by an angle (e.g., a predefined internal-tab angle) of approximately 90 degrees. External tabs include (i) a first external tab connected to a side of the coin cell and extending to overlap a top surface of the coin cell and (ii) a second external tab connected to the top surface of the coin cell. Both external tabs are positioned relative to the internal tabs to reduce an H-field and/or an E-field created by current running through the coin cell.

Inventors

Shengyin Ding
Sheba Devan

Assignees

GOOGLE LLC

Dates

Publication Date: 20260512
Application Date: 20230203

Claims (20)

1 . A battery comprising: a battery can comprising a top can and a bottom can, the top can disposed at least partially within the bottom can to provide an enclosure having a central axis, the top can defining a top of the enclosure, the top having a top exterior surface defining an xy-plane, the bottom can defining a base and a sidewall of the enclosure, the sidewall being substantially orthogonal to the xy-plane, the battery can being insulated over exterior surfaces of the battery can; a plurality of layers stacked within the enclosure between the base and the top; an internal negative tab for providing current to the plurality of layers, the internal negative tab being adjacent to a first location on an interior surface of the sidewall of the enclosure; an internal positive tab for collecting the current within the plurality of layers, the internal positive tab being adjacent to a second location on the interior surface of the sidewall of the enclosure that is different from the first location; an external negative tab connected to the top exterior surface of the enclosure at a third location and defining a negative terminal for the battery; and an external positive tab connected to an exterior surface of the sidewall of the enclosure at a fourth location and defining a positive terminal for the battery, wherein a line, which is parallel to the xy-plane and passes through the central axis and the first location, is between the fourth location and the second location.
2 . The battery of claim 1 , wherein: the external negative tab has a first shape; the external positive tab has a second shape; and the first and second shapes are configured to shape an H-field, generated by the current running through the battery, to reduce electromagnetic coupling with an electronic circuit in proximity to the top of the enclosure.
3 . The battery of claim 1 , wherein the external positive tab extends to overlap the top exterior surface of the battery can.
4 . The battery of claim 3 , wherein the external positive tab is bent to follow a contour of the enclosure from the sidewall to the top exterior surface.
5 . The battery of claim 3 , wherein: the external positive tab includes first and second portions connected together; the first portion is connected to the exterior surface of the sidewall of the battery can at the fourth location; and the second portion extends to overlap the top exterior surface of the battery can without connecting to the top exterior surface of the battery can.
6 . The battery of claim 5 , further comprising a cover that covers and insulates the first portion of the external positive tab.
7 . The battery of claim 5 , wherein the second portion of the external positive tab extends toward the central axis of the battery can.
8 . The battery of claim 1 , wherein, relative to the central axis, the fourth location, where the external positive tab is connected to the exterior surface of the sidewall, is within a range of 90 degrees to 180 degrees from the second location, where the internal positive tab connects to the interior surface of the sidewall.
9 . The battery of claim 1 , wherein, relative to the central axis, the fourth location, where the external positive tab is connected to the exterior surface of the sidewall, is within a range of −90 degrees to −180 degrees from the second location, where the internal positive tab connects to the interior surface of the sidewall.
10 . The battery of claim 1 , wherein: in a right-side battery configuration, the external positive tab and the external negative tab are seperated from the internal negative tab by a line that is parallel to the xy-plane and that passes through the central axis and the second location; and in a left-side battery configuration, the external positive tab and the external negative tab are disposed on a same side of the y-axis as the internal negative tab.
11 . The battery of claim 1 , wherein the first location and the second location are approximately 90 degrees apart relative to the central axis.
12 . The battery of claim 1 , wherein the external negative tab and the external positive tab are configured, based on the third and fourth locations, respectively, to reduce an H-field, generated when current runs through the battery, in a volume that is: on an opposing side of the x-axis from the internal positive tab; bounded by a first line extending from the central axis to the external positive tab; and bounded by a second line extending from the central axis and forming an acute angle with the first line.
13 . The battery of claim 1 , wherein the external positive tab enables the current to run from the sidewall of the enclosure to a location overlapping the top exterior surface.
14 . The battery of claim 1 , wherein the external negative tab is welded to the top exterior surface of the enclosure and the external positive tab is welded to the exterior surface of the sidewall of the enclosure.
15 . The battery of claim 1 , wherein the third and fourth locations are defined relative to the first and second locations to reduce harmonics associated with at least 800 Hertz, 1600 Hertz, and 3200 Hertz.
16 . The battery of claim 1 , wherein the battery is a coin cell.
17 . A coin cell comprising: a battery can having a positive terminal and a negative terminal, the battery can having a general cylindrical shape with a central axis; an internal negative tab disposed within the battery can and configured to connect a plurality of cathode layers to the negative terminal; an internal positive tab disposed within the battery can and configured to connect a plurality of anode layers to the positive terminal; an external negative tab connected to the negative terminal; and an external positive tab connected to the positive terminal, the external negative tab and the external positive tab being disposed at locations that are predefined relative to the internal positive tab and the internal negative tab to reduce an H-field generated when current runs through the coin cell, a line that passes through the first location and a centroid of the battery can is located between the external positive tab and the internal positive tab, the H-field being reduced in a volume over the negative terminal that is on an opposing side of the external positive tab from the external negative tab.
18 . The coin cell of claim 17 , wherein the external positive tab extends to at least partially overlap the negative terminal.
19 . The coin cell of claim 17 , further comprising an insulating layer disposed between the battery can and the external positive tab and between the battery can and the external negative tab, wherein the external negative tab and the external positive tab are each connected to the battery can via one or more weld points that extend through the insulating layer for conductivity.
20 . The coin cell of claim 17 , wherein the external negative tab and the external positive tab are configured to cause the negative terminal and the positive terminal, respectively, to be located proximate to one another on a same side of the battery can.

Description

BACKGROUND Batteries are a key component for many electronics. Coin cells (e.g., “button batteries”) with a small form factor and higher power density are becoming increasingly popular, particularly Lithium (Li) coin cells. Recent developments in small battery-powered devices include wireless earbuds, which have a very small space to package all their components, including an antenna, a main logic board (MLB), a flex circuit, a battery, a speaker module, a microphone, a contact magnet, sensors, and so forth. Challenges arise, however, in designing and producing device architecture in such small spaces for customers who generally prefer, for example, smaller, lighter, and more comfortable earbuds with a long battery life. Extending the battery life of a device generally requires using a larger-size battery. One solution is to use a system-in-package (SIP) printed circuit board (PCB), which saves space for enlarging a battery size to increase the battery life. However, a larger-size battery has more area to interface with each packaged component, which can cause issues with nearfield coupling, such as unwanted electromagnetic (EM) coupling resulting in electromagnetic interference (EMI) (e.g., crosstalk in electronic circuits). Examples of unwanted EM coupling include an E-field and an H-field from an electric current and/or a static magnetic field from the magnet. EMI may occur between various electronic components, including, for example, between the MLB and the battery, between the battery and a speaker coil of the speaker module, and/or between the flex circuit and the speaker coil. These nearfield coupling issues may be referred to as e-noise, which is an unwanted signal superimposed on a wanted signal. The e-noise may become apparent as an audible tonal noise (e.g., harmonics including 800 Hertz (Hz), 1600 Hz, 3200 Hz) via the speaker and may be recognized by a user as crackling, humming, buzzing, and/or hissing sounds, which degrades audio quality and diminishes the user experience. SUMMARY The present document describes battery configuration for reducing electromagnetic interference (EMI). The battery configuration includes a battery, such as a coin cell (e.g., stacking battery cell, button cell) with predefined external-tab configurations and a predefined internal-tab angle for reducing electromagnetic (EM) coupling. In particular, internal tabs are positioned to be separated by an angle (e.g., a predefined internal-tab angle) of approximately 90 degrees. External tabs include (i) a first external tab connected to a side of the coin cell and extending to overlap a top surface of the coin cell and (ii) a second external tab connected to the top surface of the coin cell. Both external tabs are positioned relative to the internal tabs to reduce an H-field and/or an E-field created by electric current running through the coin cell. In an example, a battery is disclosed. The battery includes a battery can comprising a top can and a bottom can. The top can is disposed at least partially within the bottom can to provide an enclosure having a central axis. Further, the top can defines a top of the enclosure and the top has a top exterior surface defining an xy-plane. The bottom can defines a base and a sidewall of the enclosure. The sidewall is substantially orthogonal to the xy-plane. Additionally, the battery can is insulated over exterior surfaces of the battery can. The battery also includes a plurality of layers stacked within the enclosure between the base and the top. In addition, the battery includes an internal negative tab, an internal positive tab, an external negative tab, and an external positive tab. The internal negative tab provides current to the plurality of layers and is adjacent to a first location on an interior surface of the sidewall of the enclosure. The internal positive tab collects the current within the plurality of layers and is adjacent to a second location on the interior surface of the sidewall of the enclosure that is different from the first location. The external negative tab is connected to the top exterior surface of the enclosure at a third location and defines a negative terminal for the battery. The external positive tab is connected to an exterior surface of the sidewall of the enclosure at a fourth location and defines a positive terminal for the battery. The central axis is between the fourth location on the exterior surface of the sidewall and the second location on the interior surface of the sidewall. In another example, a coin cell is disclosed. The coin cell includes a battery can, an internal negative tab, an internal positive tab, an external negative tab, and an external positive tab. The battery can has a positive terminal, a negative terminal, and a general cylindrical shape with a central axis. The internal negative tab is disposed within the battery can and configured to connect a plurality of cathode layers to the negative terminal. The internal positiv