About the energy density of lithium batteries

Regarding the energy density of lithium batteries, first correct a concept. Lithium is the abbreviation of what we generally call lithium batteries, and what some people call ferroelectricity is actually a lithium battery that uses lithium iron phosphate as the cathode material. It is lithium. Okay, let's start with the short version of the superficial summary: Panasonic 18650 lithium battery, with NCA as an active terminal and messy battery handling system, and then make sure and progress as efficiently and safely as possible. As for whether it is necessary to be safe, this cannot be answered. You assume that you want to talk about spontaneous combustion, but I also want to say that gasoline cars also spontaneously ignite in summer. Regarding pure electric vehicles (which can use gasoline, not to mention plug-in hybrid vehicles and pure electric hybrid vehicles), what are we most entangled with? The journey is anxious and not far away, because the energy density that the battery can store is too low. Nowadays, car battery packs generally have an energy density of 100~150Wh/kg, and the value of gasoline is about 10,000. So even if you carry a pile of batteries like a tortoise, you cannot solve this problem. Big families are making fun of what to do with electric vehicles that can’t run half of the electricity on a daily charge, but that the energy density is too low and there is little harm. The biggest shortcoming of the current battery is that the energy density is too low, far behind Moore's Law. Don’t talk about empty lithium, even if their energy density is not high enough, the key is that they are far from useful. As for why we don’t use lithium iron phosphate batteries, what I want to say is that the first reason is that the unit of capacity is Ah, and the energy (energy, is The capacity of Ah is multiplied by the voltage, and Wh) is very low. The method of car battery pack is series-parallel combination, which requires serial voltage. At this time, the consistency of the single tank voltage and the capacity of different batteries is very important. It is not prudent to say that the capacity is low. Electricity, life, cost, safety, energy. The comparative materials are NMC/NCA ternary material/NCA, LCO lithium cobalt oxide, LFP lithium iron phosphate, LMO lithium manganate. NCA and NCM are close relatives of guessing, so they are grouped here. LCOu003dLiCoO2, stratified, NMCu003dLiNixMnyCozO2, stratified, NCAu003dlini1-y-zcoyalzo2, stratified, LMOu003dLiMn2O4 spinel, LFPu003dLiFePO4 olivine energy is the lowest energy (sad drama, low capacity is One thing, 3.4V low voltage is the problem, the bad example is lithium nickel manganese acid spinel, voltage 4.7v). The length is limited, the charge and discharge curve is not shown here. The power is not low at all (some studies have overcome the pilot level of lithium iron phosphate, 5C can be reduced by 130mAh/g (of course PHOSTECH can also). The multiplier function of carbon nanomaterials is still very powerful! The best life and safety Life and safety are important because the combined use of polyanion PO43- makes the combination of oxygen better and the reactivity of the electrolyte is lower. Unlike ternary materials, it shows some oxygen bubbles more simply. In terms of the number of lives It is generally believed that it can be recycledu003e 4000 times. The cost cost, lithium iron phosphate is not bad, and the cost is second only to LMO's lithium manganese material (this thing, air combustion, manganese source is cheap), secondly competitive. Subsidiary phosphate Iron-lithium materials, lithium iron-phosphorus are relatively cheap, but nanopowders require some capital, and heat treatment must be carried out in a lazy atmosphere. Various process requirements have led to the cost of this material (about 10w/t) and Unlike the low LMO (6~7w/t), but compared with NMC (13w/t), LCO (more expensive) is still cheaper. Reason: Cobalt is more expensive than nickel (our country is poor in cobalt), and nickel is better than manganese Iron is expensive, what materials are used, and which types of capital. Then through comparison and analysis of the following NCM/NCA materials, energy is the biggest advantage (electric cars only want to run, which is the most important). In addition, with the development of high nickel NCM materials , The energy density of the material can further improve the power (in fact, for pure electric vehicles, energy is more important than power characteristics, and for hybrid vehicles like Toyota Prius, power characteristics are more important, but the premise The energy is not too bad) Longevity, not bad. Before time, ternary materials may be about 1000 times, but in recent years, with the development of research work, material life can reach 2000 weeks (such as the standard can also maintain 80% How many are still there, I don’t remember), now very handsome, electric cars, for example, you fill in one day, 365 times a year, 2000 is enough for you for six years, many people change your plan. Disclaimer: Some pictures of articles published on this site And the content comes from the Internet, if there is any infringement, please contact to delete the previous article: Analysis on Ni-MH batteries