Development Prospects of Lithium Battery Industry

This paper analyzes the application of lithium-powered batteries, which are mainly used in new energy vehicles, electric bicycles, electric tools and other fields, and provides new and energy-saving power expenditure for them. Among them, the scale of application of new energy vehicles has reached a maximum of 57 %. The proportion of electric bicycles and electric tools and other applications accounted for 14 % and 29 %, respectively. Against the backdrop of insufficient supplies of non-renewable energy and serious environmental pollution in the world, the five major development concepts of innovation, coordination, green, openness and sharing during the 13th Five-Year Plan period insisted on promoting the production and application of new energy vehicles instead of traditional ones. With the continuous increase in demand for new energy vehicles, the power lithium battery industry will have a large market space in the near future.

In recent years, due to the development advantages of lithium battery energy storage and cleanliness, it has become the leading battery technology in major application markets, including mobile equipment, grid energy storage, and electric vehicles, among which electric vehicles are the main application areas. At the present stage, the world is actively promoting the substitution and application of new energy sources. From 2014 to 2016, the global market for lithium battery power has grown from $2,831 million to $9.3 billion, with an average annual compound growth rate of 80 %. In 2017, with the expansion of global R&D and investment in new energy vehicles, it is prospective to estimate that the market size of global power lithium batteries will exceed 13 billion yuan.

With the rapid warming of the global new energy car market, major lithium ion battery manufacturers have increased their production capacity layout for automotive power batteries, and shipments have increased significantly. From the domestic point of view, under the impetus of the rapid warming of the new energy vehicle market, the shipment of lithium-ion power batteries in China in 2014 increased by 293.33 % year-on-year, reaching 5.9 GWh. With the continuous release of new energy vehicles, domestic demand for power batteries will grow rapidly. In 2016, China's shipment of power lithium batteries was about 30.5 GWh, an increase of 79.41 % year-on-year, an increase that has dropped from the previous year. In the first half of 2017, China Power Lithium Battery shipped 16GWh, and it is expected that the annual shipment volume will reach 42.8 GWh.

In 2016, ten domestic listed companies involved in the power lithium battery business announced the operating status of their company and the scale of power lithium battery business. The operating revenue of China Xuangaoke Power Lithium Battery was 4.075 billion yuan, accounting for 85.64% of the operating revenue. Increased by 90.84%. The firm's power battery business achieved operating income of 2.731 billion yuan. CITIC Guoan's Mengli Power Company achieved operating income of 1.063 billion yuan, an increase of 95.89% over the same period of the previous year. Chengfei's integrated lithium battery business revenue was 1.414 billion yuan, a year-on-year increase of 41.41%. Driven by the policy and downstream demand, enterprises operating lithium battery should pay attention to the research and development and application of battery performance to enhance the company's comprehensive competitiveness.

(1) The operating voltage of the single battery is as high as 3.7 V, which is 3 times that of the nickel-cadmium battery, nickel-metal hydride battery, and nearly 2 times that of the lead-acid battery. This is also an important reason why the lithium-powered battery is higher than the energy. Therefore, when forming a power battery with the same voltage, the number of series used by lithium-powered cells will be much less than that of lead-acid cells and nickel-metal hydride cells. If the number of cells in the power cell is higher, the higher the consistency requirement of the cells in the battery, the harder the life is to do. After the battery has a problem analysis during the actual use, It is generally one or two of the single cells that have problems and then cause problems with the entire group of batteries. Therefore, it is not difficult to understand why the 48V lead-acid battery has higher feedback than the 36V lead-acid battery. From this point of view, lithium electricity is more suitable for power batteries. Use. For example, 36V of lithium requires only 10 monomers, while 36V lead-acid cells require 18 monomer cells, that is, 3 12V batteries, and each 12V lead-acid cell has six single cells or six monomer cells..

Lithium power battery

Lithium power battery

(2) Light weight, larger than energy, up to 150 H/Kg, which is twice that of nickel-metal hydride batteries, and four times that of lead-acid batteries, so the weight is one third to one quarter of lead-acid batteries of the same energy. From this point of view, lithium consumes less resources. Moreover, due to the relatively large reserves of elements used in lithium manganese batteries, the cost of lithium-powered batteries may be further reduced compared to lead acid and nickel-metal hydride batteries. Lithium batteries for electric bicycles weigh 2.2-4 kg, lead-acid batteries weigh 12-20 kg, lithium electric weights are about one-fourth to one-third of lead-acid batteries, and are about 10 kg lighter than lead-acid batteries(36V, 10Ah batteries). The battery weight was reduced by 70 %, The total weight of the vehicle was reduced by at least 20 %. In addition, general lithium trams are simple electric bicycles. Because batteries and vehicles are light, batteries of the same voltage and capacity have longer mileage. Ordinary electric vehicles weigh more than 40 kilograms, while lithium-powered battery electric bicycles weigh 7 to 26 kilograms. Women and the elderly can easily move, manpower riding is also very light, sports leisure and both. (3) Small in size, up to 400 W/L, and one-half to one-third of the size of a lead-acid battery. Provides more reasonable structure and more beautiful shape of the design conditions, design space and possibilities. At this stage, due to the limitations of the volume and weight of lead-acid batteries, designers 'design ideas have been greatly constrained, resulting in the current phase of electric bicycles in the structure and appearance of "one thousand cars", similar to each other, and monotonous. The use of lithium batteries provides designers with more space and conditions to display design ideas and design styles. Of course, it also leads to various sizes of lithium-powered batteries for electric bicycles, which is not conducive to the development of lithium-powered batteries. The lithium-powered battery industry also needs to formulate national standards for lithium-ion batteries for electric bicycles as soon as possible to accelerate the replacement of lead-acid batteries by lithium-electric batteries in the field of electric bicycles. Of course, lithium batteries are different materials in the process of continuous development, and the volume of batteries in different processes is very different. How to unify is also a difficult point.

(4) The cycle life is long and the number of cycles can reach 1,000 times. In terms of capacity maintenance of 60 %, 100 % of battery batteries can be filled and discharged more than 600 times, with a useful life of up to 3-5 years, and a lifetime of about two to three times that of lead-acid cells. With the innovation of technology and the improvement of equipment, the battery life will be longer and longer, and the price will be higher and higher. (5) Low self-discharge rate, less than 5 % per month.

(6) Allow wide operating temperature range, good low-temperature performance, lithium-powered batteries can work between -20 °C and +55 °C, especially suitable for low-temperature use, while aqueous batteries(such as lead-acid batteries, nickel-metal hydride batteries) are at low temperatures, Due to the poor liquidity of electrolytes, performance will be greatly reduced.

(7) There is no memory effect, so you do not need to discharge like nickel-cadmium batteries and nickel-metal hydride batteries before each charge, and you can charge them anytime, anywhere. The depth of battery charge and discharge has little effect on the battery life and can be fully charged. Our cycle test is fully charged.

(8) It is particularly suitable for power cells. In addition to the high voltage of lithium cells, the protective panels of lithium power batteries can perform high-precision monitoring and low-power intelligent management of each single cell. It has perfect overcharge, over-discharge, temperature, overcurrent, short-circuit protection, lock self-recovery function, and reliable balanced charging function, which greatly extends the service life of the battery. Other types of batteries(such as lead-acid batteries) are prone to problems such as battery overcharge and over-discharge due to battery consistency, charger, etc. during use(due to various reasons such as cost, etc.). Each single cell can not be monitored and protected in a lead-acid battery pack).

(9) Unpolluted, lithium-powered batteries do not contain toxic substances, so they are called "green batteries" and are supported by the state. With lead acid batteries and cadmium nickel batteries in the presence of harmful substances lead and cadmium, the state will inevitably strengthen supervision and management(the elimination of export tax rebates for lead acid batteries, the increase in lead resource taxes, and the restrictions on export of lead acid electric bicycles), and the corresponding enterprises. The cost will also increase. Although lithium batteries are not contaminated, they are considered from the perspective of resource conservation. Lithium-powered battery recovery, safety in recycling, and cost recovery also need to be considered. (10) There are potential security risks; Due to the high energy of lithium-powered batteries and the poor stability of materials, lithium electricity is prone to safety problems. The world-renowned manufacturers of mobile phone and notebook computer batteries(positive materials are lithium cobalt acid and ternary materials), Japanese companies such as Sanyo and Sony require that the explosion rate of batteries be controlled below 40 ppb(one-billionth of a billion). Domestic companies can reach ppm(one-millionth of a million), and the capacity of power cells is more than a hundred times the capacity of mobile phones. Therefore, the safety requirements for lithium electricity are extremely high. Although lithium cobalt acid batteries and triplex batteries have the advantages of lighter weight and smaller size, they are not suitable for use in electric vehicles.

(11) High prices; Lithium-powered batteries with the same voltage and the same capacity cost 3-4 times that of lead acid. With the expansion of the market for lithium-powered batteries, the reduction of costs, the improvement of performance, and the increase in the price of lead-acid batteries, the price of lithium-powered batteries is likely to exceed lead-acid batteries.

In general, the battery voltage of the mobile phone is 3.7 V, but the voltage of the general charger is 5V, but it will not affect the use, because there is no 3.7 V mobile phone charger sold. Do not overcharge new batteries

For the "activation" of newly purchased lithium-ion batteries, there are many arguments: The charging time must exceed 12 hours and do it three times to activate the battery. This "the first three charges should be charged for more than 12 hours" is obviously a continuation of nickel batteries(such as nickel cadmium and nickel hydrogen). So this statement can be said to be misrepresented at the beginning. The charge-discharge characteristics of lithium batteries and nickel batteries are very different, and it can be very clear that all serious formal technical data emphasize that overcharging and over-discharge will cause great damage to lithium batteries, especially liquid lithium ion batteries.. Therefore, charging is best done in accordance with standard time and standard methods, especially without overcharging for more than 12 hours.

So does the battery need to be activated? The answer is yes, it needs to be activated! However, this process is done by the manufacturer and has nothing to do with the user. The user does not have the ability to complete it. The true activation process for lithium batteries is this: the lithium ion battery shell injects the electrolyte -- the seal -- into a constant pressure charge, and then discharges, so that several cycles are carried out so that the electrode is fully penetrated and the electrolyte is fully activated until the capacity is reached. Until the required, This is the activation process -- the split capacity, which means that the lithium-ion battery has been activated in the user's hand after the factory. In addition, the activation process of some of these batteries requires the battery to be in an open state. After activation, it will be sealed. Unless you have a core production device, how do you complete it?

However, why do some product instructions say that users are advised to use the first three times to completely charge and discharge the mobile phone? Isn't that activation? In fact, the fact is, when the battery is delivered, then sold, and then in the hands of the user, it will go through a period of time, a month or several months, so that the electrode material of the battery will "passivation", when the capacity is lower than normal. The use time is also shortened. However, lithium batteries are easily activated. As long as the battery is activated after 3-5 normal charge and discharge cycles, the battery can be activated and the normal capacity can be restored. Due to the characteristics of the lithium battery itself, it is determined that it has almost no memory effect. Therefore, the user's new lithium battery does not require special methods and equipment during the activation process.

The page contains the contents of the machine translation.