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How does the lithium iron phosphate battery work?
LFP Battery Safety Classification Test
Characteristics of lithium iron phosphate batteryHigh vitality density
safety
long life
Introduction
Up to now few years, electric vehicles utilizing ternary lithium batteries have skilled fireplace and explosion many instances. Therefore, the lithium iron phosphate (LiFePO4, LFP) battery, which has comparatively few unfavourable information, has been labeled as “absolutely safe” and has grow to be the first alternative for electric vehicles.
However, prior to now years, there have been frequent rumors of explosions in lithium iron phosphate batteries. Is it not a lot secure. Why is it a fireplace?
Causes and Consequences
On the whole, lithium iron phosphate batteries do not explode or ignite. LiFePO4 batteries are safer in regular use, however they don’t seem to be absolute and might be dangerous in some extreme instances. It is said to the company’s decisions of material selection, ratio, process and later uses.
Although the LiFePO4 material is thermodynamical, its thermal stability and structural stability are amongst the highest of all current cathode materials and have been verified in actual safety efficiency checks, but the possibility of quick-circuiting from supplies and batteries is inherent. And by probability, it could be the least safe.
First, from the preparation of the fabric, the solid part sintering reaction of LiFePO4 is a complex heterogeneous response with solid-phase phosphate, iron oxide and lithium salt, a carbon precursor and a decreasing fuel phase. So as to make sure that the iron aspect in the LiFePO4 is positive divalent, the sintering response must be carried out in a lowering atmosphere, and the sturdy decreasing atmosphere in the process of reducing the ferric ion to the optimistic divalent iron ion, there will likely be a constructive divalent The possibility of additional reduction of iron ions into hint elemental iron.
Elemental iron may cause the micro-brief circuit of the battery, which is the most taboo substance within the battery. This is considered one of the main the reason why Japan doesn’t apply LiFePO4e to the highly effective lithium-ion battery. In addition, a big function of the strong part reaction is the slowness and incompleteness of the response, which makes the possibility of trace Fe2O3 in LiFePO4. The Argonne laboratory in the United States attributed the defect of poor excessive-temperature cycle of LiFePO4 to Fe2O3. Dissolution throughout cost and discharge cycles and precipitation of elemental iron on the adverse electrode. As well as, in order to enhance the efficiency of LiFePO4, it’s necessary to nanoparticle its particles. A major feature of nanomaterials is their low structural and thermal stability and excessive chemical activity, which also increases the likelihood of iron dissolution in LFP to some extent, especially under excessive-temperature cycling and storage conditions. The experimental outcomes additionally present that the presence of iron is examined by chemical analysis or energy spectrum evaluation on the destructive electrode.
From the side of preparation of lithium iron phosphate battery, because the LiFePO4 nano-sized particles are small, the specific floor space is excessive, and the high particular floor space activated carbon has a powerful fuel resembling moisture within the air due to the carbon coating process. Adsorption, 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 through the charge and discharge cycle and storage of the battery, inflicting a micro quick circuit contained in the battery.
Of course, this is barely an issue in the manufacturing process, and the know-how of lithium batteries is growing rapidly. Some technologies are already glorious.
How does the lithium iron phosphate battery work?
The requirements for rechargeable batteries are:
– High capability
– High output voltage
– Good charge and discharge cycle efficiency
– Stable output voltage
High current charge and discharge
– Electrochemical stability
– Safety during use (no overcharge, over-discharge, and quick circuit) Corresponding to improper operation caused by burning or explosion)
– wide working temperature range
– Non-toxic or much less toxic
– No pollution to the setting
Lithium iron phosphate batteries using LiFePO4 because the positive electrode are good in these efficiency necessities, especially in large fee discharge (5C to 10C discharge), discharge voltage stability, safety (no combustion, no explosion), and Lipo battery pack durability (Life cycles) and eco-friendly.
LiFePO4 is used as the constructive electrode of the battery. It’s connected to the constructive electrode of the battery by aluminum foil. The middle is the separator of the polymer. It separates the positive electrode from the adverse electrode, however the lithium-ion Li+ can move and the electron e- can not cross. The suitable facet is composed of carbon (graphite). The destructive electrode of the battery is connected by a copper foil to the unfavourable electrode of the battery. Between the higher and decrease ends of the battery is the electrolyte of the battery, and the battery is hermetically sealed by a metallic casing.
When the LiFePO4 battery is charged, the li-ion Li+ in the positive electrode migrates towards the negative electrode by means of the polymer separator; during the discharge, the li-ion Li+ within the damaging electrode migrates toward the constructive electrode via the separator. Lithium-ion batteries are named after the lithium ions migrate back and forth during charging and discharging.
The operating temperature of the LiFePO4 battery, the charging atmosphere temperature: 10℃ ~ 55℃ (-20℃ for low temperature sequence); discharge atmosphere temperature: 20℃ ~ 60℃ (excessive -40℃ for low temperature).
LFP Battery Safety Classification Test
1. Anti-heavy object affect: Lithium iron phosphate battery pack shall be tested based on laws, and rechargeable battery pack shall not ignite or explode.
2. Resistance to thermal shock: The battery pack shall be examined based on the rules and shall not ignite or explode.
3. Anti-overcharge: The battery module is examined in accordance with the regulations and shouldn’t be fired or exploded.
4. Anti-quick circuit: The battery module shall be examined according to the regulations and shall not ignite or explode.
5. High-temperature storage: The battery should be examined in response to the rules, and mustn’t leak, smoke, catch fire or explode.
6. Anti-heating: The battery module is examined in accordance with the rules. If you have any issues concerning where by and how to use rechargeable battery pack; https://Www.goodreads.com/,, you can get in touch with us at our own site. No a part of the explosion battery penetrates the display, and a few or all of the batteries protrude from the display screen.
7. Anti-puncture: The LiFePO4battery pack shall be examined according to the regulations and shall not ignite or explode.
Characteristics of lithium iron phosphate battery
High power density
Its theoretical specific capacity is 170mAh/g, the actual specific capacity of the product can exceed 140mAh/g (0.2C, 25℃);
It’s presently the safest lithium-ion battery cathode material; it does not include any heavy metallic parts harmful to the human body.
Under 100% DOD conditions, it may be charged and discharged more than 2000 times.
The service life of LiFePO4 battery is carefully related to its use temperature. If the use temperature is too low or too excessive, it would cause nice disadvantages in its charging and discharging course of and use course of. Especially utilized in electric autos in northern China, in autumn and winter, the LiFePO4 battery cannot be powered normally or the power provide is just too low, and its working surroundings temperature must be adjusted to keep up its efficiency. At current, the home answer to the fixed temperature working surroundings of LiFePO4 battery wants to think about the space limitation drawback. The extra common solution is to use aerogel felt as the insulation layer.