We here at Cheers and Gears have covered plenty of battery companies in existing or startup form. We even covered places where one could invest some spare coin if interested in taking high risks with these battery tech companies. After all the Golden Goose is the battery company who delivers ICE like charging to an EV battery pack.

Every University has groups of people working on their PhD, Doctorate, Masters, etc. in one field or another. Harvard University had a team of scientists that took on the challenge and have now moved from thesis / conceptual theory to working prototype in founding Adden Energy. This team of scientists have developed a solid-state battery and the process to scale up into commercial production a battery cell that delivers on two major fronts:

1. Battery pack charge time as low as 3 minutes
2. Capacity retention for over 10,000 cycles

Adden Energy has developed this cutting-edge technologies to enable mass adoption of EVs around the world and contribute greatly to a cleaner future.

Professor Xin Li's research group at Harvard School of Engineering and Applied Sciences started studying solid-state batteries in 2015.

• Doctoral students William Fitzhugh and Luhan Ye played leading roles in the technology development process.
  • Several impactful innovations on solid-state batteries have been discovered by this group
• Fred Hu, PhD in economics from Harvard and Founder of Primavera Capital joined and advised the team to commercialize the technology portfolio in a Startup Company.
• Adden Energy incorporated in 2021
• Adden Energy received first round funding

Adden Energy had the following experimental and theoretical discoveries in battery thermodynamics and Kinetics allowing this group to develop a new field of mechanical constriction design of battery materials and devices.

Battery Material papers:

• Advanced sulfide solid electrolyte by core-shell structural design | Nature Communications
• Strain‐Stabilized Ceramic‐Sulfide Electrolytes - Fitzhugh - 2019 - Small - Wiley Online Library

Devices papers:

• Toward Higher Voltage Solid‐State Batteries by Metastability and Kinetic Stability Design - Ye - 2020 - Advanced Energy Materials - Wiley Online Library
• A more stable lithium anode by mechanical constriction for solid state batteries - Energy & Environmental Science (RSC Publishing)

The new design approach drastically improves stability of the solid-electrolyte and battery system by carefully controlling the mechano-electrochemical environment of solid-state batteries. This team has created an innovative multi-electrolyte-layer separator with a dynamic stability design.

• A dynamic stability design strategy for lithium metal solid state batteries | Nature
• Synergistic effects of chlorine substitution in sulfide electrolyte solid state batteries - ScienceDirect
• A Two-Parameter Space to Tune Solid Electrolytes for Lithium Dendrite Constriction | JACS Au

New machine learning and high-throughput computational chemistry algorithms have predicted and can design more novel solid-electrolytes with improved performance.

• A High‐Throughput Search for Functionally Stable Interfaces in Sulfide Solid‐State Lithium Ion Conductors - Fitzhugh - 2019 - Advanced Energy Materials - Wiley Online Library
• Solid–electrolyte-interphase design in constrained ensemble for solid-state batteries - Energy & Environmental Science (RSC Publishing)
• A Two-Parameter Space to Tune Solid Electrolytes for Lithium Dendrite Constriction | JACS Au

Adden Energy's technological break throughs are allowing this startup to scale from a college lab R&D into a commercially acceptable sized cell. These technical advances have spanned material design and synthesis, in-house solid-electrolyte development, and novel cell designs. Combined material and device innovations have enabled the demonstration of the technology with high-current-density lithium metal anodes as well as high voltage cathodes.

What does this mean to you, the auto enthusiast? 

As per their press release that was in Physicsworld website: Sandwich strategy makes solid-state lithium battery last longer – Physics World

Long life, the battery cells are expected to allow battery packs on average to last 10-15 years without loss of cells, thus giving EVs similar life as found with Diesel and Gas auto's.

Charging, the battery tech that Adden Energy is ramping up means that the average auto would be looking at a 5 to 10 minute fast charge capable over and over with no degradation in the battery. Large size auto's like Trucks or SUVs would be 10 to 20 minutes.

Researchers design long-lasting, solid-state lithium battery – Harvard Gazette

Current EV battery tech can cause Dendrites to form, shortening the battery life when subjected to large constant high-speed charging. Adden Energy solution is a thicker multilayer between the anode and cathode, much like a BLT sandwich.

To quote the Harvad Gazette story: Think of the battery like a BLT sandwich. First comes the bread — the lithium metal anode — followed by lettuce — a coating of graphite. Next, a layer of tomatoes — the first electrolyte — and a layer of bacon — the second electrolyte. Finish it off with another layer of tomatoes and the last piece of bread — the cathode.

The first electrolyte (chemical name Li_5.5PS_4.5Cl_1.5 or LPSCI) is more stable with lithium but prone to dendrite penetration. The second electrolyte, (Li₁₀Ge₁P₂S₁₂ or LGPS) is less stable with lithium but appears immune to dendrites. In this design, dendrites are allowed to grow through the graphite and first electrolyte but are stopped when they reach the second. In other words, the dendrites grow through the lettuce and tomato but stop at the bacon. The bacon barrier stops the dendrites from pushing through and shorting the battery.

“This proof-of-concept design shows that lithium-metal solid-state batteries could be competitive with commercial lithium-ion batteries,” said Li. “And the flexibility and versatility of our multilayer design makes it potentially compatible with mass production procedures in the battery industry. 

A drawing of comparison between Adden Energy battery tech and todays traditional Lithium-ion batteries with the current battery on the left and Adden Energy blocking dendrites on the right.

End result is that while the first generation of EVs will be slower to charge and have possible shorter battery life, the future for moving to solid-state batteries is bright with ultra-fast charging times and long life.

Adden Energy