Designed specifically for wearable devices, Ningde New Energy flexible battery!

With the development of science and technology, various electronic products have emerged and are almost indispensable in daily life. Lithium-ion batteries have the advantages of high energy density, long cycle life, environmental friendliness and renewability, and have been widely used in various electronic products.

Batteries for wearable electronic devices need to be flexible enough to fit the shape of the wearable device and accommodate changes in shape and volume when the wearable device is in use. Conventional batteries with liquid electrolytes are not flexible enough to meet the requirements of wearable devices, and batteries with gel or solid electrolytes suffer from low energy density and poor ion mobility.

Therefore, people hope to have batteries with high flexibility while maintaining high energy density and power density to meet the needs of portable and wearable electronic devices.

In order to meet such needs, CATL applied for an invention patent entitled "Flexible Battery for Wearable Devices" (application number: 201810885472.8) on August 6, 2018, and the applicant was CATL Technology Co., Ltd.

Based on the currently disclosed patent information, let’s take a look at this flexible battery technology.

As shown in the figure above, it is a schematic diagram of the first electrode, the partition and the second electrode for manufacturing a flexible battery, which includes a first electrode 100 of the battery, a separator 118 and a second electrode 110. The first electrode includes a plurality of sections, including a first coated section 105 and a second coated section 109, which are interconnected by an uncoated section 106 between the first and second sections.

The first coated section, the uncoated section, and the second coated section are sequentially arranged along the X direction, and the three can also be formed by coating the first active material 122 on the surface of the first current collector 104. The uncoated section corresponds to the uncoated portion of the first current collector, and the first electrode further includes a tab 107, which is attached to the uncoated section.

As shown in the above figure is a schematic cross-sectional view of a flexible battery, it can be seen that the battery 140 includes a first battery cell 102 and a second battery cell 103 interconnected by a connector 126. The connector 126 is disposed between the first battery cell and the second battery cell along the X direction and electrically connected between the first battery cell and the second battery cell.

For each of the first battery cell and the second battery cell, an electrolyte is disposed between two electrodes, and the packaging film 130 is used to seal and package the battery. The battery 140 can be formed by sequentially stacking the first electrode 100, the separator 118, and the second electrode 110 in the Y direction.

The first battery cell includes a first segment 105 of a first electrode, a first segment 115 of a second electrode, a portion of a separator, and an electrolyte disposed between the first and second electrodes.

The second battery cell includes the second segment 109 of the first electrode, the second segment 119 of the second electrode, a portion of the separator, and an electrolyte disposed between the first and second electrodes.

Next, let’s take a look at the three-dimensional schematic diagram of the flexible battery.

As shown in the figure, the length of the connector 126 along the X direction is as long as the distance between the first battery cell and the second battery cell. When the battery is deformed, such as bent, stretched or slightly rotated, the folding structure of the connector can bend, stretch or twist accordingly to adapt to the shape and volume changes without causing mechanical or electrical failure or plastic deformation to the battery material.

Next, let’s take a look at how this flexible battery is applied in specific wearable devices.

It can be seen that the curved battery is formed by a die forging process (e.g., metal stamping) as shown in the above figure. One or more dies are usually used to form the battery. The battery 140 can be heated to a certain temperature during the bending process. The packaged battery is placed between the concave die 152 and the convex die 150, and a predetermined pressure or force is applied to bend the battery to give it a certain curvature.

When the battery is applied in a specific wearable device, such as a smart bracelet, as shown in the above figure, multiple flexible batteries 640 are distributed on multiple curved parts 632 of the wearable device 630, thus achieving a perfect application of the flexible battery.

The above is the flexible battery invented by CATL, which is formed by connecting conventional battery cells with a flexible connector in the middle. The flexible connector can have a folding structure and can be bent into a certain curvature to match the shape change when using wearable devices. This flexible battery has many advantages and can still power various wearable devices with good energy density, reliability and safety after multiple cycles!