Custom Lithium ion Battery Pack

There are several types of lithium-ion batteries for lithium-ion electric vehicles

Feb 11, 2019   Pageview:19

Lithium iron phosphate batteries than Tesla MODELS using the ternary lithium batteries in much higher energy density, weight is about 200 wh/kg, this means that the same weight of ternary lithium battery range is longer than the lithium iron phosphate batteries.But its shortcomings are obvious, when its temperature is 250-350 ℃, internal chemicals began to decompose, thus puts forward high requirements on battery management system, the installation of insurance device need batteries separately for each section, in addition, due to the monomer volume is small, so the bike to battery monomer quantity is very large, MODELS, for example, more than 7000 day18650 the ternary lithium battery to meet the dosage of the assembly of a car, no doubt this again for the battery management system is further increased the difficulty of control.Cars on sale in the market at present, therefore, is only one Tesla is using ternary lithium battery.

Ni-Mh batteries is another mainstream at present except the lithium battery electric vehicles power battery species, in the 1990 s after the gradual development, such as many represented by the Toyota prius hybrid car adopts such battery as an energy storage element.Its energy density and the normal lithium battery gap is not large, about 70-70 wh/kg, but as a result of monomer battery voltage is only 1.2 V, is the 1/3 of lithium batteries, so in certain cases, the demand voltage of the battery pack some volume than lithium batteries.

As with lithium battery, nickel metal hydride battery also need battery management system, but pay more attention to the battery charge and discharge management.Exists such a difference, mainly from the Ni-Mh batteries have "memory effect", namely the battery capacity will appear in the process of circulation charge and discharge attenuation, and excessive charge or discharge, is likely to increase battery capacity loss (lithium batteries the characteristic almost negligible).So for vendors, nickel metal hydride battery control system will take the initiative to avoid excessive charge and discharge in the set, such as the battery charge and discharge interval artificially controlled within a certain percentage of the total capacity, in order to reduce capacity attenuation speed.

Fuel cell is not "battery", accurately, a large power system.Due to high energy conversion efficiency, no pollution, long service life, stable operation, etc by the industry recognized as the best energy future.In simple terms, the fuel cell is convert chemical energy to electrical energy by chemical reaction, a device and a source of energy is mainly rely on the continuous supply of fuel and oxidant.

In theory, fuel cells can use has a variety of fuel, and even traditional fuel used in internal combustion engine, but really to electrochemical reaction, is just one of the oxidant oxygen and hydrogen, therefore, hydrogen fuel cell is the core current fuel cell research.

In terms of the market today, fuel cell car is not far from us.According to the previously reported, the world's first production fuel cell car Toyota FCV formal sales in Japan in March next year.The vehicle is equipped with two 70 mpa high-pressure reactor, the output power of 122 ps (90 kw), battery can reach 700 km JC08 conditions (Japan).In addition, the fuel only 3 minutes, compared with the traditional electric vehicle charging time to get a lot.Associated with various policy in Japan at present also successively formulated for cashing, domestic when to buy is unclear, however, can only wait for some time.

Physical battery

Physical battery, as the name implies, is to rely on to provide a physical change, battery referred to store electrical energy, such as super capacitor, the flywheel battery belong to physical members of the family of the battery.

The super capacitor power density high but the battery capacity is small

Super capacitor is a kind of between traditional capacitance and battery power components, mainly depend on the electric double layer and REDOX false charge to store electrical energy capacitance, does not occur during chemical reaction, therefore is classified as physical category of the battery.Compared with the previously introduced chemical battery, super capacitor three obvious advantages, first of all, its repeated charge and discharge amount to hundreds of thousands of times, the traditional chemical battery only a few hundred to several thousand times), are much higher than chemical batteries on life;Second, the super capacitor during charge and discharge of high power density, moment can release a lot of energy, can meet the power demand of vehicles more broad;Third, better ability to adapt work environment, usually outdoor temperature 40 ℃ - in - 65 ℃, it can be stable work (traditional battery is commonly - 20 ℃ ~ 60 ℃).

Has the advantages of course, there will be less than, the low energy density is the primary bottleneck restricting the development of super capacitor, so, at present the main applied to vehicle launch system, military, and a small amount of public transport vehicles, as for whether it can be used as a family car power supply, still need a breakthrough for problems such as energy density is known.

Flywheel battery is currently only used as a secondary battery

Flywheel battery is a new concept put forward in the 1990 s battery, also belongs to a kind of physical energy.Is simply by using the principle of similar flywheel turns to produce energy to realize own charge and discharge.In October 2010 in the final round of the American le mans series, porsche 911 gt3 hybrid car is the first official use flywheel battery technology, which is famous as a forerunner of the porsche 918 spyder.But these two models are only for the use of auxiliary energy of flywheel battery, its function is similar to our common braking energy recovery system.Even so, we still have reason to believe that, with the continuous development of technology and further reduce the price, will be a wide prospect in the application of flywheel battery.

Lithium electricity no matter from price, security, have no advantage on range, or lead.

The advantage of lithium electricity, light weight, cycle life may reflect not to come out on electric bicycles.

If you really want to buy electric bicycle lithium electricity, or to buy foreign brand batteries, such as Sanyo, Samsung, etc.

According to the positive pole material system, usually with ternary material, lithium iron phosphate, manganese acid lithium materials;

Comprehensive performance comparison:

Battery safety can be three kinds of material,, the safety of the lithium manganese acid lithium iron phosphate is better;

Manganese acid lithium battery life relative to the other two are the worst, is also the cheapest;

Lithium iron phosphate is the comparison of fire of fire, but comprehensive speaking is not very mature;Lithium iron phosphate life is good, but its low temperature discharge performance is poorer, when used in a comparatively cold zone, can release the power of less proportion, appear small capacity;

Batteries ternary materialIn price, security, life, the respect such as production technology is neutral, and the same * capacity (voltage) specification is not same type of battery, the weight of the batteries ternary material with volume is far less than the other kinds of battery, personally think that the most suitable current Li-ion battery power battery should be batteries ternary material.

Divide from cell structure type, cylindrical, rectangular steel shell, flexible packaging (polymer) batteries, etc.;The main is a mix of these batteries.Square steel shell with more, cylindrical, there are many soft package is also good, should be a kind of trend of development;A variety of merits for evaluation, personal bias flexible packaging (polymer) batteries.

The lithium battery has 3 kinds: the ternary material portable lithium polymer battery;Lithium manganese acid lithium batteries;Lithium iron phosphate batteries.Xi DE Sheng is ternary lithium polymer battery.

Electric vehicle battery is divided into two broad categories, batteries and fuel cells.Battery is suitable for pure electric vehicles, including lead-acid battery, nickel metal hydride batteries, sodium sulfur batteries, lithium secondary battery, air batteries.

Fuel cell is dedicated to the fuel cell electric vehicles, including alkaline fuel cell (AFC), phosphoric acid fuel cell (PAFC), molten carbonate fuel cell (MCFC) and solid oxide fuel cell (SOFC), proton exchange membrane fuel cell (PEMFC), direct methanol fuel cell (DMFC).

With a slightly different with the types of electric vehicles.In only equipped with a battery of pure electric vehicles, battery of motor drive system is the only source of power.In the traditional equipment engine (or fuel cell) hybrid cars with the battery, the battery can play the role of motor drive system main power source, can also act as the role of auxiliary power supply.Visible in the low speed and startup, battery is a major power motor drive system of the role of the;In the full load acceleration, act as the role of auxiliary power supply;When moving or deceleration, brake act as a role of storing energy.

Fuel cell by the fuel in the anodic oxidation and antioxidant in the cathodic reduction.If at the anode (negative external circuit, also can say fuel is) on the continuous supply of gaseous fuel (hydrogen), and at the cathode (namely the positive, of the external circuit can also be called air extremely) on a continuous supply of oxygen (or air), can continuously produce electrochemical reaction on the electrode, and an electrical current.Thus, fuel cells and conventional electricity

Pool is different, its fuel and oxidant is not stored in the battery, but is stored in the battery outside of the tank.When it work (output current and power), transport into the cell needs to continuously fuel and oxidant and discharge reaction product at the same time.Look from the way to work, therefore, it was similar to the conventional gasoline or diesel generators.Due to the fuel cell to continuously work to the battery into the fuel and oxidant, fuel cells using fuel and oxidant are fluid (gas or liquid).The most common fuel for pure hydrogen, various FuHanQing gas (such as reforming gas), and some liquid (e.g., methanol aqueous solution), commonly used oxidant for some pure oxygen, purify air and other gas and liquid (such as hydrogen peroxide and nitric acid aqueous solution, etc.).

Fuel cell anode is used for fuel and electrolyte of public interface, and the catalyzed oxidation of fuel, at the same time, the reaction of the electronic transmission to the external circuit or transferred to the current collector first and then to the external transmission.The role of oxygen electrode (cathode) is to provide public interface for oxygen and electrolyte, catalyzed reduction of oxygen, oxygen electrode reaction from the external electromagnetic approach parts transmission electron.Due to the electrode reaction happened mostly polyphase interfacial reaction, in order to improve the reaction rate, porous materials commonly used electrode and catalyst coated with electricity.

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