The age-old 100 in X takes on a new meaning in an all-electric future

Blog Post
Amir Tirosh, COO

The automotive industry loves numbers. Whether it’s manufacturing capacities, efficiencies, or six-sigma, someone, somewhere has these safely tucked away in the company’s archives. But it is not only industry analysts that regularly refer to metrics, enthusiasts also turn to figures when debating relative performance and how cars have improved over time.

Hence, the acceleration from standstill to 100 mph in 4.3 seconds achieved by the Tesla Model S Plaid, is often cited as a measure of how far the automobile has progressed when compared to the 100 mph in 17.8 seconds recorded by the Alfa-Romeo Disco Volante in 1953.

And in a world rapidly moving toward electrification the ubiquitous “100 in X” is set to take on a new meaning with consumers who expect cars to match their user experience in other areas of their digital lives. This time, as a realistic measure of charging performance and progress in delivering range when needed. The importance of which should be seen in the light of consumers’ two key concerns when switching to electric vehicles - range- and charge-anxiety. 

The future of the EV relies on Extreme Fast Charging. Image Source: DOE

Consequently, as the leader in extreme fast charging (XFC) battery technology, StoreDot has modernized the familiar “100 in X” to represent “the time, in minutes, to add 100 miles of range during a charging event.” By so doing a lot of the confusing and often ambiguous jargon surrounding charging is now reduced to a simple and familiar expression.

Moreover, having carefully analyzed current and future EV ecosystems we have laid out an easy-to-follow roadmap for future charging performance to create an experience identical to that of traditional gas-powered cars. Based on our extreme fast charging (XFC) battery’s silicon-dominant anode technology and the progress being made with the “extreme energy density” semi-solid battery, we have set the following key milestones, expressed in terms of “100 in X”:

  • 100 Miles charged in five minutes by 2024
  • 100 Miles charged in three minutes by 2028
  • 100 Miles charged in two minutes by 2032

StoreDot’s Extreme Fast Charging roadmap. Image Source: StoreDot

Key battery improvements driving “100 in X” 

When discussing the time to charge, energy density and total battery capacity are critical factors to be considered. And while there is obviously a wide range of battery capacities, over the next few years the increase in energy density will largely be determined by the improvement in the performance of the anode and cathode. Thus, silicon-dominant anodes and ternary cathodes, such as lithium nickel cobalt manganese, are expected to continue to drive the progress in battery cell energy densities.

LiB energy densities continue to rise. Image Source: BNEF

Based on what we know about current and nascent battery development we expect to see the energy density (when subjected to slow charging) of these batteries increase from about 240Wh/kg in 2021 to a little over 300Wh/kg in 2024. Over the same period, the nominal pack capacity will likely increase from 60kWh to over 75kWh.

Similarly, the industry charge-rate is anticipated to improve from roughly 2.4C to 3.0C, with industry-wide charge times for 100 miles reducing from 16.7 minutes in 2021 to around 9 minutes in 2024. However, StoreDot’s silicon-dominant anode technology in the XFC battery could slash that to about 5 minutes at 6.3C by 2024.

The arrival of our ‘100in3’ high energy density battery pack in about 2028 will signify another quantum leap forward in battery performance. With a projected energy density of around 450Wh/kg, the nominal battery capacity is anticipated to reach 92kWh, with the time to charge to 100 miles cut to about 3 minutes – an improvement of 40 percent, before reducing to 100in2 (a further 33 percent reduction) by 2032.

100 Miles in 2 minutes, within a decade

Rounding out the 10-year outlook on battery performance and charging, we expect StoreDot’s battery to achieve a slow-charge energy density of 700Wh/kg in a pack with a capacity of 160kWh by 2032. In this form StoreDot’s ‘100in2’ battery is expected to add 100 miles in approximately 2 minutes – halving the industry’s forecast of four minutes.

And with a potential range of 990 miles the electric vehicle, powered by StoreDot’s energy-dense battery, will have met and even exceeded consumers’ range-per-charge expectations, thereby laying to rest concerns over range and charge challenges.

However, even though battery development is key to the success of the EV, it forms part of a larger ecosystem that must also progress in lockstep with the battery.

An industry wide effort required to support 100inX charging

Whereas the design and chemistry of the battery pack play an important role in determining the time to charge the battery safely, external factors such as the output power of the charge-station and the current-carrying capacity of the charging-cable and plug, all have to support extreme fast charging to enhance the user experience and ensure the rapid global adoption of EVs.

Currently, for Level-3 DC-charging the Combined Charging System (CCS) specification supports up to 400A continuously at 1,000V for 400kW, although several companies make CCS chargers that can output up to 500A.

In Asia, a joint development between the predominantly Japanese CHAdeMO Association and China’s State Grid utility operator seeks to increase this to 900kW at 1,500V and 600A.

DC fast chargers continue to power ahead. Image Source: Electrek

At these levels of power, last-mile delivery to charging stations for cluster charging will require significant updates to infrastructure, such as power-cables and transformers. In some cases off-grid solutions such as renewable energy and hydrogen fuel cells with battery storage may be required, coupled with bi-directional smart-charging and billing.

The final piece needed to complete the 100inX puzzle lies with the design of the EV, in particular the energy efficiency of the vehicle, measured in Wh per mile. An EV’s efficiency depends on a wide range of different factors including the size and weight of the vehicle and its aerodynamics and the ability of its electrical engineers to design and build highly efficient motors, inverters, and electronic control systems. 

According to the online publication, Battery Technology, in 2022 the most efficient EVs are in the low to mid 200Wh/mi range (derived from battery capacity and EPA-quoted range), while the least efficient are above 300Wh/mi. Obviously, vehicles that use less energy to propel the car, also require less energy during charging to achieve 100 miles of range.

So even though the progress of the EV is happening at an unprecedented pace, the industry must continue to work toward a transformative product that will overcome the major barriers to the widespread adoption of electric vehicles – charging times and range anxiety, allowing manufacturers to offer consumers a ‘Range On Demand™’ user experience. What is more, global automotive manufacturers must have a clear, realistic, and hype-free roadmap for the introduction of fast-charging battery technologies. To this end, StoreDot’s ‘100inX’ is a metric that not only lays out the route but also adds the milestones in a familiar yet easy-to-understand format.