Pacific Automotive Network uses the same battery structure, using ternary materials and lithium iron phosphate materials to manufacture batteries, and conducts discharge, charge and cycle tests under different conditions. Ternary materials have different charge rates, discharge rates and cycles. and it has advantages in temperature discharge performance, and lithium iron phosphate materials have better cycle performance. It can still maintain more than 80% of the initial capacity after 5000 cycles at 1°C.
After 30 years of development, lithium iron phosphate lithium ion batteries have significantly improved their specific energy, specific power and other properties, and have been successfully used in automobiles . Limited by the specific energy of the battery, the autonomy of purely electric vehicles is limited, whichi constitutes a bottleneck limiting development. Recent projects by foreign automakers mainly aim to develop hybrid vehicles.
The cathode materials currently used in lithium-ion batteries mainly include lithium manganese oxide, lithium iron phosphate, lithium cobalt oxide, ternary materials and other materials . Currently used electric battery cathodes mainly use lithium iron phosphate and ternary materials. .Yuan two materials. This article uses the same battery case cover, negative electrode material and internal structure design to make batteries with two cathode materials, lithium iron phosphate and ternary, and compares the specific energy, the specific power, cycle, high and low temperature characteristics of the two batteries. . Comparison Analyzethe differences in performance between the two batteries.
(a) Discharge curve of ternary material battery (b) Discharge curve of lithium iron phosphate battery Figure 1 Rate discharge curve Table 1 Battery discharge data 2.2 Comparison of charging performance As shown in Figure 2 and Table 2, ternary materials When the battery and lithium iron phosphate battery are charged at no more than 10C, there is no obvious difference in the charging capacity ratio at constant current/total capacity. When charging at a rate above 10C, constant current charging. The capacity to total capacity ratio of the lithium iron phosphate battery is smaller, and the higher the charging rate. The larger the ratio of constant current charging capacity to total capacity, the more obvious the gap with the ternary material battery. at low voltage change of lithium iron phosphate at 30% ~ 80% SOC. For example, if soft carbon or hard carbon is used for the negative electrode, iron phosphate. The high-rate charging performance of lithium batteries can reach the ternary level. batteries.
(Images/Text/Photos: Pacific Automotive Network Calling the Beast Q&A)