Exploring the cost of lithium batteries for mobile devices

The cost of lithium batteries for mobile devices (with photos) Lithium polymer batteries are ubiquitous in mobile phones, tablets, laptops, and hybrid/electric vehicles. We rarely consider them, unless it involves consumer electronics, such as smart watches. Today’s smartwatches are the same as some laptops, with a battery life of less than a day. This reminds me of the battery problem and whether smartwatches, mobile phones, and tablets all have batteries. This also stimulated our curiosity: can we use a variable to budget the cost of battery manufacturing (BoM)? A short-term use variable may include the quality of the battery or the charging capacity, both of which are very short measurements. The pouch-type lithium battery commonly found in smartphones was taken with the disassembled iPhone6Plus. The strip containing the control circuit connected to the battery has been removed, but it can be seen in Figure 2. We noticed that this battery uses two Ricoh battery maintenance ICs and TI lithium battery voltmeter. Our first question is: What are the special features of this battery? In order to find the answer, we tested the battery energy density of several smartphones and tablet devices that were removed in the laboratory in the past year ( Wh/g). As shown in Figure 3, many mobile phone/smartphone batteries weigh less than 25 grams, while tablet computer batteries weigh more than 70 grams. The diagonal represents 220Wh/kg, which is equivalent to the energy density of most batteries. From these scattered but closely connected points, it can be seen that they use very similar battery technology. The battery of the iPhone 6Plus weighs 43 grams, and its energy density is not particularly obvious, but it is worth a look because it belongs to Apple. Our next focus is on the battery material bill; for this, we need to know more about the structure of the battery. In Figure 4 below, we begin to disassemble the lithium battery of the iPhone6Plus. We peeled off the aluminum foil on the outside of the battery to expose the polymer film that sealed the battery inside. After the polymer film is peeled off, it is exposed to a set of aluminum cathode electrical outer layer (aluminum cathode collector), as shown in FIG. 5. LiCoO2 is a complex battery technology that usually appears in behavioral devices, including mobile phones, tablets, and laptops, which explains that the energy densities of the devices shown in Figure 3 are very similar. The following table shows some other cathode materials. The bottom three are the cathode materials for electric vehicle batteries, using lithium manganese oxide (LMO) and lithium nickel manganese oxide (NMC). Graphite anodes and cobalt oxide cathodes have a lattice structure in which lithium ions can rotate into the vacancies between atomic layers. FIG. 9 is a microscope image of the cobalt oxide layer at the cathode of the battery, and the structure of the graphite layer at the anode is shown in FIG. 10. The budgetary bomb cost of mobile phone lithium batteries is not such a short thing. There have been some discussions about electric vehicle batteries, but the right to pay for a smaller battery capital budget, one is in 2015, Chen pointed out that the shape of the capital base ( ev) Lithium battery is about 0.5 dollars per watt hour (Wh). We often disassemble and analyze devices such as smart watches, smart phones, tablets, and laptops, and add up the parts to calculate the cost of materials. Therefore, we budgeted battery manufacturing costs by subtracting these benefits. Going back to our first question, can the simplest proxy variable be used for material cost? We think the answer should be yes. Judging from the concentration state of lithium battery cost shown in Figure 11, this should be reasonable; The cost also includes materials and labor, which we think will increase with the capacity of the battery. Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: Tips on drone battery controller