How does the lithium iron phosphate battery work?
LFP Battery Safety Classification Test
Characteristics of lithium iron phosphate batteryHigh energy density
security
lengthy life
Introduction
Prior to now few years, electric automobiles using ternary lithium batteries have skilled fireplace and explosion many instances. Therefore, the lithium iron phosphate (LiFePO4, LFP) battery, which has comparatively few negative news, has been labeled as “absolutely safe” and has turn into the primary alternative for electric automobiles.
However, previously years, there have been frequent rumors of explosions in lithium iron phosphate batteries. Is it not much secure. Why is it a fireplace?
Causes and Consequences
Basically, lithium iron phosphate batteries do not explode or ignite. LiFePO4 batteries are safer in normal use, however they are not absolute and could be harmful in some excessive cases. It is related to the company’s choices of material selection, ratio, process and later uses.
Although the LiFePO4 material is thermodynamical, its thermal stability and structural stability are among the best of all current cathode supplies and have been verified in precise security performance checks, but the potential of brief-circuiting from materials and batteries is inherent. And by likelihood, it would be the least safe.
First, from the preparation of the fabric, the stable section sintering reaction of LiFePO4 is a complex heterogeneous reaction with strong-part phosphate, iron oxide and lithium salt, a carbon precursor and a lowering gasoline part. In order to make sure that the iron aspect within the LiFePO4 is constructive divalent, the sintering response have to be carried out in a decreasing environment, and the strong reducing atmosphere in the technique of lowering the ferric ion to the optimistic divalent iron ion, there will be a constructive divalent The possibility of further reduction of iron ions into trace elemental iron.
Elemental iron could cause the micro-quick circuit of the battery, which is the most taboo substance in the battery. That is considered one of the principle explanation why Japan doesn’t apply LiFePO4e to the highly effective lithium-ion battery. As well as, a significant function of the stable part response is the slowness and incompleteness of the response, which makes the potential of hint Fe2O3 in LiFePO4. The Argonne laboratory in the United States attributed the defect of poor high-temperature cycle of LiFePO4 to Fe2O3. Dissolution throughout charge and discharge cycles and precipitation of elemental iron on the unfavourable electrode. In addition, in order to enhance the performance of LiFePO4, it is necessary to nanoparticle its particles. A major function of nanomaterials is their low structural and thermal stability and high chemical activity, which also will increase the chance of iron dissolution in LFP to some extent, particularly beneath excessive-temperature cycling and storage circumstances. The experimental outcomes additionally show that the presence of iron is tested by chemical analysis or vitality spectrum evaluation on the damaging electrode.
From the facet of preparation of lithium iron phosphate battery, because the LiFePO4 nano-sized particles are small, the specific surface space is high, and the excessive particular floor area activated carbon has a strong gas equivalent to moisture in the air as a result of carbon coating process. Adsorption, lithium ion battery news resulting in poor electrode processing performance, the adhesion of the binder to its nanoparticles is poor. The nanoparticles are simply detached from the electrode during the battery preparation course of or in the course of the charge and discharge cycle and storage of the battery, causing a micro brief circuit inside the battery.
In fact, this is barely a problem within the production process, and the know-how of lithium batteries is creating quickly. Some technologies are already glorious.
How does the lithium iron phosphate battery work?
The necessities for rechargeable batteries are:
– High capacity
– High output voltage
– Good cost and discharge cycle efficiency
– Stable output voltage
High current cost and discharge
– Electrochemical stability
– Safety throughout use (no overcharge, over-discharge, and quick circuit) Comparable to improper operation brought on by burning or explosion)
– broad working temperature range
– Non-toxic or less toxic
– No pollution to the setting
Lithium iron phosphate batteries utilizing LiFePO4 because the optimistic electrode are good in these efficiency requirements, especially in large price discharge (5C to 10C discharge), discharge voltage stability, safety (no combustion, no explosion), and sturdiness (Life cycles) and eco-pleasant.
LiFePO4 is used because the optimistic electrode of the battery. It is related to the optimistic electrode of the battery by aluminum foil. The middle is the separator of the polymer. If you treasured this article so you would like to be given more info regarding lithium ion battery news please visit the web-page. It separates the constructive electrode from the destructive electrode, however the lithium-ion Li+ can pass and the electron e- cannot move. The precise side is composed of carbon (graphite). The adverse electrode of the battery is connected by a copper foil to the adverse electrode of the battery. Between the upper and lower ends of the battery is the electrolyte of the battery, and the battery is hermetically sealed by a metal casing.
When the LiFePO4 battery is charged, the li-ion Li+ in the constructive electrode migrates toward the unfavourable electrode by means of the polymer separator; throughout the discharge, the li-ion Li+ within the unfavourable electrode migrates towards the positive electrode by means of the separator. Lithium-ion batteries are named after the lithium ions migrate again and forth during charging and discharging.
The operating temperature of the LiFePO4 battery, the charging atmosphere temperature: 10℃ ~ 55℃ (-20℃ for low temperature series); discharge environment temperature: 20℃ ~ 60℃ (excessive -40℃ for low temperature).
LFP Battery Safety Classification Test
1. Anti-heavy object impression: Lithium iron phosphate battery pack shall be tested in response to rules, and shall not ignite or explode.
2. Resistance to thermal shock: The battery pack shall be tested in line with the regulations and shall not ignite or explode.
3. Anti-overcharge: The battery module is examined in keeping with the rules and shouldn’t be fired or exploded.
4. Anti-short circuit: The battery module shall be tested based on the rules and shall not ignite or explode.
5. High-temperature storage: The battery should be examined in response to the laws, and shouldn’t leak, smoke, catch fireplace or explode.
6. Anti-heating: The battery module is examined in response to the regulations. No a part of the explosion battery penetrates the display, and some or all of the batteries protrude from the display.
7. Anti-puncture: The LiFePO4battery pack shall be tested in accordance with the laws and shall not ignite or explode.
Characteristics of lithium iron phosphate battery
High vitality density
Its theoretical particular capability is 170mAh/g, the actual particular capacity of the product can exceed 140mAh/g (0.2C, 25℃);
It’s at the moment the safest lithium-ion battery cathode materials; it doesn’t include any heavy metallic parts dangerous to the human physique.
Under 100% DOD conditions, it may be charged and discharged more than 2000 instances.
The service life of LiFePO4 battery is closely related to its use temperature. If the use temperature is simply too low or too excessive, it would trigger nice disadvantages in its charging and discharging process and use course of. Especially utilized in electric automobiles in northern China, in autumn and winter, the LiFePO4 battery cannot be powered normally or the power provide is too low, and its working atmosphere temperature must be adjusted to maintain its performance. At present, the home resolution to the fixed temperature working setting of LiFePO4 battery wants to contemplate the area limitation problem. The more common resolution is to make use of aerogel felt because the insulation layer.