Re-examining rates of lithium-ion battery technology improvement and cost declines

Title	Re-examining rates of lithium-ion battery technology improvement and cost declines
Authors	Micah S. Ziegler , Jessika E. Trancik
Date	07/27/2020
Introduction	Lithium-ion technologies are increasingly utilised for electrifying transport and providing stationary energy storage for electrical grids, thus attracting substantial attention to their advancement. However, their current deployment remains relatively limited, with broader adoption contingent on their capacity for cost reduction and performance enhancement. Understanding this potential is crucial for informing critical climate change mitigation strategies, including public policies and technology development efforts. Many existing models of cost decline, however, rely on limited data series and measures of technological progress. This study systematically collects, harmonises, and combines various data series regarding the price, market size, research and development, and performance of lithium-ion technologies. We then establish representative series for these measures and employ performance curve models to quantify improvement rates. To achieve a broader estimate of technological progress, additional performance characteristics were incorporated into these models, notably energy density and specific energy metrics. When energy density is included in the definition of service provided by a lithium-ion cell, estimated technological improvement rates increase considerably, suggesting that previously reported rates might understate the pace of change in lithium-ion technologies. Furthermore, our estimates allow for a rough quantification of the degree to which lithium-ion technologies' price decline might have been limited by performance requirements other than cost per energy capacity. These rates also suggest an approximate estimate for how much faster costs might decline when advancing battery technologies for stationary applications, where restrictions on mass and volume are relaxed, though engineering-based mechanistic cost modelling is required to further characterise this potential.
Quote	Micah S. Ziegler and Jessika E. Trancik. Re-examining rates of lithium-ion battery technology improvement and cost declines. 2020.
Element	Lithium (Li)
Industry	Energy Storage & Batteries , Automotive , Research & Laboratory