Will lithium iron phosphate compete with lithium manganese oxide for market share?

The price of lithium iron phosphate continues to decline, while lithium manganese oxide has been soaring. Recently, they met at the point of 70,000 yuan/ton. How will they develop next?

Since 2017, affected by overcapacity, the price of lithium iron phosphate has continued to decline. As of April 2018, the mainstream transaction price in the market has reached 75,000 yuan/ton, and some manufacturers' products shipped to the energy storage field are as low as 70,000 yuan/ton. In sharp contrast, the lithium manganese oxide market has been booming in production and sales. According to Xinlang Information statistics, the domestic production of lithium manganese oxide reached 35,000 tons in 2017, a year-on-year increase of 34%, and high-end power products also rose from 60,000 yuan/ton to 70,000 yuan/ton.

Comparing the cost-effectiveness of lithium iron phosphate and lithium manganese oxide was almost unimaginable in the past two years. Now that the prices of the two are so close, it seems reasonable to compare them.

First, let's look at the main performance differences between the two

Energy density

In terms of energy density, lithium manganese oxide and lithium iron phosphate have always been comparable. Lithium iron phosphate has a higher gram capacity, but its voltage is lower, and the two phases cancel each other out. However, since the compaction density of lithium manganese oxide is significantly higher than that of lithium iron phosphate, the volume-to-energy ratio of lithium manganese oxide is still much higher than that of lithium iron phosphate. In addition, lithium iron phosphate has a smaller energy density loss during high-rate discharge, and its performance is significantly better than that of lithium manganese oxide.

Comparison of available energy density at different discharge rates

Cycle performance

Cycle performance has always been the strong point of lithium iron phosphate, and lithium manganese oxide cannot compete with it. Under normal humidity and high temperature conditions, the capacity of lithium iron phosphate batteries degrades significantly slower than that of lithium manganese oxide batteries over the cycle period. Under high temperature conditions, the degradation of both batteries is significantly accelerated. Judging from the data, the service life of lithium iron phosphate batteries is 2-3 times that of lithium manganese oxide batteries.

Return data of 1C charge and discharge cycle capacity of lithium manganese oxide and lithium iron phosphate batteries

High and low temperature performance

From the experimental data, we can see that in both low-temperature environments of -20 degrees and high-temperature environments of 55 degrees, the degradation of lithium manganese oxide batteries is relatively stable, and is basically controlled within 10%. On the contrary, lithium iron phosphate batteries only perform well in high-temperature environments, and the degradation is very obvious at low temperatures.

Voltage curve at -20 degrees and 55 degrees

Summarize

On the whole, the overall evaluation of the performance of lithium manganese oxide is mediocre, with average energy density, average cycle performance, acceptable high and low temperatures, and a reasonable price. It looks like a good child who is not picky about food and does not hate food. However, lithium iron phosphate is very distinctive, with average energy density, outstanding cycle performance, high temperature stability, and low temperature performance. We believe that when the price of lithium iron phosphate gradually approaches that of lithium manganese oxide, the watt-hour cost alone is not much different. If the battery volume requirement is not high, the obviously better cycle performance makes the battery life cost lower. In this context, lithium iron phosphate is most likely to impact part of the commercial vehicle market share occupied by lithium manganese oxide. In addition, it will also replace it in some high-rate power battery fields. (Author: Hu Junlong, Xinrong Information)