Lithium-ion technologies are increasingly employed to electrify transportation and provide  stationary  energy storage for electrical grids, and as such their development has garnered much attention. However,  their deployment is still relatively limited, and their broader adoption  will depend on their potential for cost reduction  and performance improvement. Understanding this potential can inform critical climate change mitigation strategies, including public policies and technology development  efforts.  However,  many  existing  estimates  of past cost decline, which often serve as starting points for forecasting models, rely on limited data series and measures of technological progress. Here we systematically  collect,  harmonize,  and combine  various  data  series of price, market size, research and development, and performance of lithium-ion technologies. We then develop representative series for these measures, while separating  cylindrical  cells  from all types  of cells. For both,  we  find that the real price of lithium-ion cells, scaled by their energy capacity, has declined by about 97% since their commercial introduction in 1991. We estimate that between 1992 and 2016, real price per energy capacity  declined 13% per year for both all types of cells and cylindrical cells, and upon a doubling of cumulative  market size, decreased 20% for all types of cells and 24% for cylindrical cells. We also consider additional performance characteristics including energy density and specific energy. When energy density is incorporated  into  the  definition of service provided by a lithium-ion battery, estimated technological improvement rates increase considerably. The annual decline in real price per service increases from 13 to 17% for both all types of cells and cylindrical cells while learning rates increase from 20 to 27% for all cell shapes and 24 to 31% for cylindrical cells. These increases suggest that previously reported improvement rates might underestimate the rate of lithium-ion technologies’ change. Moreover, our improvement rate estimates suggest 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 that  battery technologies developed for  stationary applications,  where restrictions on volume and mass are relaxed, might achieve faster cost declines, though engineering-based mechanistic cost modeling is required to further characterize this potential. The methods  employed  to  collect these data and estimate improvement rates are designed to serve  as a blueprint  for  how to work  with  sparse data when making consequential measurements of technological change.


This analysis combines data from and reconciles differences between 90 series that describe how lithium-ion technologies have changed and possible drivers of that change. Representa- tive series that track changes in price, market size, patent filings, and cell-level energy density and specific energy were constructed for all types of lithium-ion cells and in most cases also for cylindrical cells, allowing us to compare trends in this important subgroup to those observed for all cell shapes. By combining and harmonizing data from a variety of sources, we sought to develop more reliable estimates of technological change and improvement rates for lithium-ion technologies. Moreover, by clearly delineating how these representative series were constructed, we aim to provide a methodological framework that can be extended, both as additional data on lithium-ion technologies are collected and to other technologies.


Energy storage technologies have the potential to enable greenhouse gas emissions reductions via electrification of transportation systems and integration of intermittent renewable energy resources into the electricity grid.


 In the future, JUNLEE Energy, which has been committed to battery research and development, is a challenge and an opportunity. The R&D team of engineers will provide the world with more economical new energy batteries, and will improve lithium-ion battery technology to reduce the total cost.


JUNLEE Group is an integrated full power energy factory that specializes in Uninterruptible Power Supply(UPS),Lead-Acid Battery, Battery pack,EV battery, Energy Storage Battery, Energy storage power station, Power pack Gel battery, PV Inverter and Solar system.

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