A few days ago, at MWC20 15, China manufacturers made a splash. First of all, there are rumors that Gionee will release S7 to achieve 4.6mm and regain the title of the thinnest mobile phone in the world. However, for reasons of balance, Gionee's S7 actually only achieved 5.5mm, and did not pursue impractical ultra-thin. However, another manufacturer, also from China, caused a sensation. Dragonfly mobile phones that have cooperated with 360 in China are mainly for innos in overseas markets, and innos D6000 was launched, but it won the title of mobile phone with the largest battery capacity in the world with 6000mah dual batteries. In recent years, with the improvement of the performance of smart phones, the battery life problem of mobile phones has become more and more serious. People's habit of smart phones has changed from three days to one day, and they have to bring a charging treasure when they go out. With a heavy charging treasure, the charging experience of connecting the data cable to the mobile phone "hanging bottles" and "hanging urine bags" is really bad. As a result, various manufacturers have made great efforts in structural design and battery technology, hoping to make the battery bigger and have a better battery life, which has led to the evolution of the battery capacity of mobile phones. First, the secret of the battery lithium battery is actually a small category of batteries from a professional point of view. The battery consists of a positive electrode, a negative electrode and an electrolyte. There are few kinds of electrolytes. One is the traditional electrolyte, which we call lithium-ion battery, and there is no other name. The other is the organic polymer as electrolyte, but the organic polymer is no longer liquid, so we call it lithium polymer battery or lithium-ion polymer battery. These are two types. Lithium polymer battery has higher capacity, and it will not explode at high temperature because there is no liquid, so its safety is relatively better. Under the two categories, according to the different cathode materials (mostly graphite), it can be divided into lithium cobalt oxide lithium-ion batteries (polymer, not added later, the same below), lithium manganate lithium-ion batteries, ternary lithium-ion batteries and lithium iron phosphate lithium-ion batteries. These batteries have their own advantages and disadvantages, some have good safety and some have strong overload capacity, but what mobile phones require is capacity and price, so at present, our mobile phone batteries are basically large-capacity lithium cobalt oxide batteries. It is best to use polymer as electrolyte. The cheaper electrolyte has not much difference in energy density and has no breakthrough technical advantages. Although with the development of technology, the energy density and voltage of the battery will increase slightly every year, the most direct way to improve the battery capacity is to increase the battery volume. A large battery is needed for a large amount of electricity. A large battery must have a large volume, and the improvement brought by technological advantages is minimal. Second, the evolution of mobile phone structure Because of the limited size of manpower, the length, width and thickness of mobile phones have limits. To make the battery bigger, it is necessary to compress the volume of other parts of the mobile phone. This is the evolution of mobile phone structural design. In the era of functional machines, the contradiction of battery life is not prominent, and first-class enterprises do not value battery capacity. Because of the special national conditions, China began to design large-capacity battery mobile phones very early. For example, the domestic Changhong Long Power Series. At that time, the practice of Changdian was simply to increase the thickness. 20mm is called brick, which has a long standby time, but its portability is greatly reduced. When mobile phones evolved into the era of smart phones, people began to think of ways from the structure. Apple's approach is to build a battery, sacrifice the replaceable function, remove a layer of plastic at the bottom of the battery compartment, and reduce the thickness of the mobile phone. In this way, a larger battery can be inserted under the same thickness, or the same battery capacity can be made thinner. A better way is to make the mobile phone itself thinner. For example, Motorola's RAZR makes the mobile phone thinnest through a large single-layer circuit board, and then it can keep the thickness of the battery, and a little increase in thickness can make RAZR MAXX have a lot of electricity at that time. Xiaomi 2 actually draws lessons from this design, but the disadvantage of this design is that the main chip is covered by the battery, and the heat dissipation will be a bit problematic. With the increase of smartphone screen, the battery area is getting bigger and bigger. In the past, 3.5-inch mobile phones achieved 2000mah, which was considered as a super-capacity battery. Now it is very common for 5.5-inch and 6-inch mobile phones to achieve 3000mah. The 7-inch Huawei x2 battery has a capacity of 5000mah, which can actually be considered as a small flat panel. Modern mobile phones are relatively thin, and the battery capacity of mobile phones is obtained by reducing the area of circuit boards. With the same thickness, the smaller the area of the circuit board, the larger the space left for the battery. Huawei is an expert in this field. Huawei can always install more batteries for the same size mobile phone. Third, the secret of 6000mah The innos D6000 screen released on MWC20 15 is not large. Generally, mobile phones over 5 inches are around 2500mah. Innos D6000 not only achieves 6000mha, but also can replace the battery. How did it do it? In fact, innos made a D9 mobile phone in 20 12, and 4 160mah was also the largest battery record at that time. The secret of the year was to thicken the battery of ultra-thin mobile phones. In the structural design of the mobile phone, try to make the circuit board above the mobile phone, leaving more space below, and then make the other structures of the mobile phone thin, leaving the thickness for the battery, but the thickness of that D9 exceeds 14mm, which is really too thick. This time, the design of D6000 is even more brilliant, and the dual battery is a very interesting design. First, the mobile phone is designed as an ultra-thin semi-circuit board, and then a small-capacity battery is stuffed under it. Turn into an ultra-thin mobile phone with a protruding camera. This is also the design method of many mainstream mobile phones. If this is the end, then the D6000 will be a 2000mah ultra-thin mobile phone. Innos added a second battery. Because the first battery is flush with the circuit board, the second battery can cover almost the whole mobile phone (except the top camera part) because it is not contained by the circuit board, and it can have amazing battery capacity without too much thickness. By combining these two kinds of batteries, a 6000 mAh battery with a thickness of 1 1.9 mm can be made. What's more frightening is that it can be replaced. Users bring a mobile phone and a small built-in battery of 4000mah, which is equivalent to taking out a 10000mah mobile power supply, and there is no need for an external charging cable, and there will be no power failure. It's really a good design. The additional advantage of this structure is that because the mobile phone is very thick, the camera can be very thick without protruding, so innos can use a high-quality camera with better quality and larger CMOS area to improve the image quality. In addition, because the two batteries are independent, the power supply and charging can be designed separately, so that the charging speed can be faster, and each battery can complete rapid charging without bearing too much current. However, this structure also has disadvantages, because the second battery covers the circuit board, and the heat dissipation of the circuit board is blocked (similar to RAZR MAXX and Xiaomi 2), and the heating problem with too strong CPU performance will be more serious. So innos D6000 uses Qualcomm MSN8939, which is A53 core and eight nuclear, with low power consumption. Less heat, less power consumption, and better battery life. Fourth, it can be better. Innos D6000 is already a mobile phone with excellent design. It is difficult to achieve 6000mah with a 5.2-inch screen with 1 1.9 mm, but the best distance is still a little distance, because its design does not make the processor performance reach the top level. In fact, it would be better to change the design of the circuit board slightly under the scheme of innos D6000, that is, to change the design of the circuit board and divide it into high heating area and low heating area. The high heat area and camera are at the top, the battery has no cover, and the thermal conductive graphite is directly attached to the metal back cover. In this way, a high-performance processor and a large battery can be used at the same time, and the unification of a high-performance CPU, a high-performance camera and a large-capacity replaceable battery can be realized. If the processor can be combined with the improved design of innos D6000, MTK will produce the high-performance processor A72 A53 in the second half of the year. This product will be very attractive.