Introduction: Scholars reviewed the historical price development of lithium-ion batteries and found that the accepted model does not accurately reflect all the cost reductions and technological improvements that have occurred. Through more data points to compare, the research team found that the improvement of the battery even exceeded the previous hypothesis.
According to researchers from the Massachusetts Institute of Technology, the cost of lithium battery energy storage has fallen by 97% since it was put into the commercial market in 1991. They proposed a new methodology to support their claim. The previous model underestimated the cost. Decline.
In order to draw conclusions, the researchers added more data series and indicators to the price calculation. The standard model only considers the price of each energy capacity drop (in USD/kWh). However, the MIT team considered additional data points, including specific energy and energy density figures, to better determine the degree of improvement in lithium-ion technology. The first striking result of their research is that lithium-ion batteries are improving much faster than previously assumed.
For example, from 1992 to 2016, researchers added energy capacity and energy density to the consideration of standard cost development. They concluded that the average annual cost reduction measured by "actual price per service" was about 17%, instead of the 13% previously estimated. The price of each service refers to the dollar figure per unit of energy capacity and is a function of the volume per unit of energy capacity. Taking into account the energy density in the calculation, a higher figure of 17% was obtained.
It is understood that the learning rate of cylindrical batteries is about 24%, and that of other types of batteries is about 20%. However, the MIT team took the additional indicators into account and observed an increase to 30% and 26%, respectively. This change is partly attributable to previous estimates, which are characterized by problems in calculating the number of batteries that are being introduced to the market. This is because batteries of different sizes are produced for different applications, which can be confusing when comparing different devices in a standard price development model.
The results of the study led the MIT team to believe that the reported improvement rate may underestimate the fast-paced development of battery technology. The scientist said: "In addition, our improvement rate estimates indicate that the price drop of lithium-ion technology may be limited by performance requirements other than the cost of unit energy capacity."
Collecting data from articles, reports, academic reports, government publications, and business literature enables researchers to incorporate more data points into a more comprehensive cost development model. The team systematically collected, unified and combined various data series related to price, market size, R&D, and lithium-ion technology performance.
The analysis summarized 90 data series related to lithium battery prices, market size, patent applications, battery-level energy density, and specific energy development. The researchers suggest that in the future compilation of data sets, they should adopt their more comprehensive methods.
