As the most representative car company in the domestic new energy field, BYD has a complete "three power" technology. In battery technology, BYD has always adhered to the lithium iron phosphate battery route in the past few years, and the technology is very mature. In the past two years, due to changes in the subsidy policy, it has to follow the market trend, which is equivalent to the “half-way home” research and development of ternary lithium batteries, but now it has also achieved “later”, and its “811” battery research and development has made some progress. .
However, recently BYD said at its performance exchange meeting that a new generation of lithium-lithium batteries will be launched in May-June next year. When the news came out, it immediately caused widespread concern. Today, the ternary lithium battery has become the mainstream. What is the meaning of BYD regaining the lithium iron phosphate battery?
In fact, compared to the ternary lithium battery, the lithium iron phosphate battery has higher safety, longer cycle life and lower cost, but the energy density has less room for improvement. According to China's new energy subsidy policy, battery energy density is an important factor in how much subsidies are obtained.
The existing anode materials for lithium ion batteries are mostly graphite, and the theoretical capacity of graphite is 372 mAh/g. The lithium iron phosphate battery and the ternary lithium battery are substantially the same on the negative electrode material. However, on the positive electrode material, the theoretical capacity of lithium iron phosphate is only 160 mAh/g, while that of nickel cobalt manganese is as high as 200 mAh/g. In addition, production process levels such as compaction density, foil thickness, etc., also affect energy density. But overall, the difference in performance of the cathode material is the decisive factor.
It is reported that BYD's new generation of lithium iron phosphate battery energy density can reach 180Wh / kg, compared with the previous increase of about 9%, this data is not weaker than the "811" ternary lithium battery.
According to the latest new energy subsidy policy in 2019, without considering the factors such as cruising range, as long as the battery energy density reaches 160Wh/kg and above, one-time subsidy can be obtained, and the double subsidy is also the highest amount. In view of this, in fact, BYD has been able to achieve the highest standard of energy density, that is, to receive full subsidies.
In contrast, the lithium iron phosphate battery thermal runaway temperature is generally above 500 degrees, the ternary lithium battery is less than 300 degrees, some high nickel ternary lithium battery thermal runaway temperature is even lower than 200 degrees, which will increase the vehicle speed And the risk of spontaneous combustion during fast charging.
BYD relies on its leading position in the battery field and perfects the consistency of the battery. The iron-lithium battery developed from the product design, equipment to production process, management process to ensure the consistency of the battery pack, so that the single battery The safety, life and battery pack are consistent, fully meeting the requirements of automobiles, forklifts and energy storage power stations.
BYD lithium iron phosphate battery has a longer life than the whole vehicle and is easy to charge. It is understood that "Qin" is equipped with lithium iron phosphate battery, the structure is still stable at 600 ° C high temperature, its safety is much safer than the lithium cobalt oxide battery installed in ordinary mobile phones and notebooks.