Tesla BYD's batteries are lagging behind?

The battery has been the development of electric vehicles in the heart pain

Based on the current charging infrastructure under the condition of immaturity, electric cars for more consumer recognition, limited driving distance is the key factor, WH ich largely depends on the performance of the battery. Battery technology restrict the development of electric vehicles, this is all to common problems faced by enterprises for the development of electric vehicles, auto makers and battery suppliers are seeking technology breakthroughs. Over the years, we have witnessed the rise of group after group of batteries and decay, and some died early, some still struggling in the laboratory, some in the market constantly updated but unsatisfactory, WH en I can make a breakthrough, battery technology is still unknown, perhaps three years, maybe five years, also may be longer.

At present, the electric car battery mainly includes at present Lithium iron phosphate batteries、Batteries ternary material, lead-acid batteries, sodium sulfur batteries and other traditional battery, of course, represent the future of science and technology of fuel cell and a new type of liquid battery, etc., and their advantages and disadvantages caused by the performance of different difference is quite big. The current mainstream models mainly carry the lithium iron phosphate batteries and batteries ternary material. Low density of lithium iron phosphate, was only around 120 WH /kg, but the advantage is good thermal stability, high safety. Three Yuan  energy density materials can reach 150 WH  ~ 200 WH , limited driving distance is long, but its disadvantage is that security issues. Industry of ternary material and the relative merits of lithium iron phosphate has been divided.

October 30, 2014, the international strategy and investment group released a statement, said the United States electric car maker Tesla's motor car annual output will reach 500000 units, Which will make the materials used by the three Yuan  (NCA aluminum nickel and cobalt) battery costs fell by about 30%.Tesla claims profit last year, this year is more good news, the numerous car companies choose the battery on the lead role. In the first half of this year, Chinese car companies have turned to the ternary material. In 2014, the existing Jianghuai, chery, baic, zhongtai, says one all the manufacturers in the latest models using ternary material.

Recently, the author will introduce new battery technology for statistical findings: after new material and improve the existing lithium ion battery, battery is becoming the trend of the development of the electric car, with the launch of the new battery technology, the future trip range of electric vehicles are expected to increase greatly.

The darling of the lead-acid battery: low-speed electric cars

Lead-acid battery is safe, cheap, and long after 150 years development, made a great contribution to human beings. Lead-acid battery is one of the batteries we are most familiar with, the main advantage is that the voltage stability, the price is cheap, but at the same time it still has lower than can frequent, short service life and maintenance, etc.

Lead-acid battery once misunderstood in China. A lot of people think it backward old, environmental pollution, so for a period of time, the technology development of lead-acid batteries. In recent three years, our government has earnestly rectify lead-acid battery industry, gradually perfect the laws and regulations, shut down the large number of small businesses, strict access for lead-acid batteries; The existing enterprise pollution, optimize the industrial hygiene, do civilization production enterprises, in the continuous improvement of the lead pollution situation. Lead-acid batteries are 2 v, 4 v, 6 v, 8 v, 12 v and 24 v series, MAH from 200 to 3000 MAH capacity, although the price is low, but limited driving capacity of a battery is low. So, gradually abandoned by electric vehicles. Lead-acid batteries, however, in the domestic application of low-speed electric cars are still very common.

Nickel cadmium battery: economic and durable but poisonous

Nickel cadmium battery can be repeated charge and discharge more than 500 times, very economy; Small internal resistance, for large current discharge; Because the completely sealed, so there will be no electrolyte leakage phenomenon, does not need to supplement electrolyte; Placed for a long time will not degrade performance; Can be used in a wide range of temperatures. But, if not handled properly in the process of charging and discharging, there will be a serious "memory effect", greatly shorten the service life. In addition, cadmium is toxic, and nickel cadmium battery is not conducive to the protection of the ecological environment, using the abandoned after will cause pollution to the environment.

The dharma of nimh battery: a hybrid car

Ni-mh battery is made up of hydrogen ion and nickel metal, 30% more reserves than the nickel cadmium battery, more light than nickel-cadmium batteries, longer service life, and no pollution to the environment. The disadvantage of nimh batteries are much expensive than the nickel cadmium battery, performance is worse than lithium battery. Ni-mh battery is mainly used in hybrid electric vehicle (HEV) and consumer electronics products two fields, HEV applications occupy more than 90% of the share, commercial representative is the Toyota prius.

lithium iron phosphate battery: the electric car battery upstarts

Lithium iron phosphate batteries belong to lithium ion secondary battery, mainly used for power battery, high efficiency and its discharge, discharge case to charge and discharge efficiency can reach more than 90%, While lead-acid batteries is about 80%.In the battery, the safety of the lithium iron phosphate battery is higher than other batteries, theory of life can reach 7 ~ 8 years, the actual service life is about 3 ~ 5 years, cost performance in theory for lead-acid battery more than four times. Disadvantage is that the lithium iron phosphate battery price is higher, and the battery capacity is small, short line continuation mileage, and discarded after basically cannot be recycled, there is no recycling value. To sum up, the application of lithium iron phosphate batteries in electric cars, can make the overall cost of ascension, and the battery cannot be recycled, so will cause the waste of resources and consumption.

Lithium iron phosphate industry in China has developed rapidly, from the number of patent applications submitted an application for a patent for the lithium iron phosphate field in the world's number, but in the global main supplier of lithium iron phosphate, but I did not see the figure of Chinese enterprises. That is to say, although our country in this area to submit relevant patent application number, but the quality needs to be improved, truly realize the industrialization of less number of patents.

Cobalt acid lithium batteries: Tesla's VIP

Cobalt acid lithium batteries has stable structure, capacity than high, comprehensive performance is prominent, but its poor safety and cost is very high, it is mainly used for medium and small type batteries, nominal voltage of 3.7 V.

The Tesla electric vehicle battery used Panasonic NCA series, aluminum nickel and cobalt system provided by the 18650 cobalt acid lithium batteries, single battery capacity is 3100 MAH. Tesla adopt the strategy of the battery pack, the MODELS of 85 KWH  battery unit USES the 8142 total of 18650 lithium-ion batteries, engineers will first these batteries with brick, one by one, the average distribution of the WH ole battery pack, battery pack is located in the deck. Tesla engineers within the battery pack insurance device of distribution to each section 18650 cobalt acid lithium batteries, each section 18650 cobalt acid lithium batteries both ends is equipped with a fuse, WH en the battery overheat or current is too large, the fuse will cut off, so as to avoid the abnormal situation for a battery (overheating or current is too large) affect the entire battery pack. In this view, cobalt acid lithium batteries While defects existing in itself, but in Tesla engineer on the packaging of safety basically can be ignored. Apparently, the solution is suitable for use in pure electric vehicles.

Titanium acid lithium battery: the discrimination policy in decline

Lithium Titanate (LTO) is not the anode material, but substitutes tradition - graphite anode materials. Lithium titanate for battery development began in the 1990 s, compared with graphite anode, lithium titanate has long cycle life, safety, quick charging multiple advantages. Battery in the charger, discharge, the cathode lithium ions embedded and emergence process exist .Layered structure of graphite materials in lithium ion embedded hernia usually produces deformation between the layers, and with the increase in the number of embedded to take off the structure collapse. And lithium titanate is a zero strain material, lithium ion embedded in and out WH en the lattice constant and the volume changes are small and have excellent cycle performance. Lithium titanate charging time is short and long cycle characteristics on the electric bus of short to show adequately. But because of the discrimination policy, a new round of subsidy scheme, after the issuance of the lithium titanate quick charge pure electric bus quota subsidies than after falling 350000 Yuan  subsidy standard, lithium titanate pure electric bus lost the advantage of competition in the market, the technology also gradually underdog.

Fuel cells: clean and efficient but high cost

Fuel cell is a kind of will exist in the chemical energy of the fuel and oxidant directly into electrical energy power generation device. The fuel and air were sent to the fuel cell, electric was wonderfully produced. It viewed from the outside is the cathode and the electrolyte, etc, like a battery, but it can't essentially "storage" but a "power plants".

For fuel cells convert chemical energy of fuel into electricity directly, without burning process, and thus is not limited by carnot cycle. The fuel cell system in fuel - power conversion efficiency was 45% ~ 60%, and the efficiency of coal-fired power andspecial power at about 30% ~ 40%.The disadvantage is that the cost of fuel cell is on the high side, hydrocarbon fuel can not directly use, hydrogen storage technology limited and insufficient hydrogen fuel infrastructure, etc. The most is expected to be used in automobile is proton exchange membrane fuel cell.

Sodium sulfur battery: higher than energy is not a general

Sodium sulfur battery is a kind of metallic sodium as the anode, sulfur as the anode, ceramic tube for electrolyte secondary battery of the diaphragm. Work in a certain degree, sodium ions through the electrolyte membrane and reversible reaction between sulfur, form of energy release and storage. Sodium sulfur battery is a high specific energy, and large current, high power discharge. But its working temperature at 300 ~ 350 ℃, so the battery work needs certain heat insulation.

Bit Tesla liquid battery: energy density of lithium batteries as 5 times as large

Liquid battery by a soaked the electrochemical activity of the electrode in glass containers filled with liquid electrolyte composition of the battery. Most of the cell, including the use of batteries, laptop computer and the TV remote control is used by solid materials such as zinc or lithium cobalt ACTS as the cathode, anode and graphite as liquid salt solution as electrolyte membrane. While the liquid battery is different, the Yin and Yang and membrane are liquid, and is the hot melt like mud liquid. Liquid battery charging high energy density, stable and durable, faster, more environmental protection, can maintain more than 14000 cycles. The disadvantage is the high cost.

In this year's Geneva motor show, developed by Liechtenstein energy company Nano Flowcell AG Quant. E – Sport limousine concept supercar. New car with 2900 cows, peak torque, hundreds of kilometers acceleration time just 2.8 seconds, a charge can run 400 to 600 kilometers. The car's biggest bright spot is that it USES Nano Flowcell - AG company developed a new type of liquid electrolyte battery. The battery using brine as energy storage medium. Salt water will charge by diaphragm between two tank formation and electricity is stored and assigned to the super capacitor. Its energy density 5 times larger bit Tesla lithium batteries, and it is more stable and durable, charging speed faster, but also more environmentally friendly.

Graphene battery: full of mobile phone battery only about five seconds at a time

Graphene is a kind of configuration and interconnected by carbon atoms, in accordance with the hexagon and carbon molecules, its structure is very stable, belong to the new materials, the most thin, the hardest known material, electrical conductivity and best nano materials with strong flexibility. Because of its low resistivity, electron transfer speed, surface area and good electrical properties, scientists think is ideal electrode material of lithium ion batteries. The expert inside course of study introduces, graphene composites used in lithium ion battery cathode materials can be greatly increased and large capacitance rate charge and discharge performance of anode materials. Application of graphene to lithium ion battery, full of a mobile phone battery probably only need 5 seconds; To Tesla all-electric cars charge, may be just a few minutes. It is understood that the Tesla new batteries will be using graphene material, its high conductivity and good flexibility, is one of the ideal candidate for the material of flexible energy storage device.

Aluminum air battery: the highest battery can reach 1600 km

The page contains the contents of the machine translation.