Volkswagen-backed Battery Startup QuantumScape Develops Solid State Technology With the Potential to Increase EV Range by 80%

author: Eric Walz   

Silicon Valley-based solid state developer and newly listed public company QuantumScape Corporation has shared the performance data of its advanced solid-state lithium-metal EV battery design for the first time on Tuesday. 

QuantumScape's newly released performance data demonstrates that its high-energy density solid-state EV batteries can deliver much faster charging times, longer cycle life, higher safety and operation in a wide range of temperatures without degradation. 

The company's solid state batteries have the potential to increase an EVs range by 80% from the current lithium ion batteries in use today, as well as offering 15 minutes charging times. 

The technology could lead to the mass adoption of electric vehicles in the next decade as a commercially-viable solid-state lithium-metal battery will enable electric vehicles with a driving range comparable to combustion engine based vehicles.  

The design also offers higher energy density than any current batteries in production, including those made by Tesla. The company's data indicates that the solid state battery technology is capable of lasting hundreds of thousands of miles. 

The batteries can also operate at a wide range of temperatures, all the way down to -30 degrees Celsius (-22 Fahrenheit). These extreme temperatures render some other solid-state battery designs inoperable, according to QuantumScape.

"We believe that the performance data we've unveiled today shows that solid-state batteries have the potential to narrow the gap between electric vehicles and internal combustion vehicles and help enable EVs to become the world's dominant form of transportation," said Jagdeep Singh, founder & CEO of QuantumScape. 

QuantumScape was founded in 2010. For the past ten years the company exclusively focused on developing advanced solid-state batteries, as well as designing a scalable manufacturing process to mass produce them. 

The company entered into a joint venture partnership with German Vokswagen to produce the batteries at scale. One of the long term targets of the joint venture is to establish a production line for solid-state batteries by 2025.

The solid state batteries design replaces the traditional separator inside of a battery and replaces with a ceramic material separator layer. This layer separates the positive and negatively charged anode and cathode material and eliminates the need for conductive anode. 

In this type of battery architecture, an anode of pure metallic lithium is formed when the finished cell is charged, rather than when the cell is produced. 

Once this solid state ceramic separator layer is in place, the negatively charged carbon or silicon-based anode material is not needed. In its place is an electrical contact. As the lithium passes through the separator it gets deposited in a solid layer between the separator and electric contact, forming an anode of pure metallic lithium.

It allows QuantumScape to build smaller solid state EV batteries without a traditional anode material. This results in a battery with a smaller physical volume but with a much higher energy density.

QuantumScape's solid-state separator is also non-combustible and isolates the charged lithium layer from the cathode even at very high temperatures—much higher than conventional organic separators used in lithium-ion batteries today, the company said.

QuantumScape's solid-state design increases energy density because it uses no excess lithium on the anode. Some previous attempts at solid-state batteries used a lithium foil or other deposited-lithium anode, which reduces energy density.

The performance tests were conducted using large-area single-layer pouch cells in their target commercial form factor running at rates of one-hour charge and discharge (1C charge and 1C discharge) at 30 degrees Celsius. According to QuantumScape, the tests demonstrated robust performance of the pouch cells resulting in retained capacity of greater than 80% after 800 cycles in the freezing temperatures.

The newly released test results show that QuantumScape's solid-state separators are capable of working at very high rates of power, enabling a 15-minute charging time, as current can move rapidly through the separator.

"These results blow away what was previously thought to be possible in a solid-state battery," said Venkat Viswanathan, battery expert and professor of materials science at Carnegie-Mellon University. "Supporting high enough current density to enable fast charge without forming dendrites has long been a holy grail of the industry. This data shows the capability to charge to 80% capacity in 15 minutes, corresponding to an astonishingly high rate of lithium deposition of up to a micron per minute."

The dendrites Viswanathan is referring to are tiny, rigid tree-like structures that can grow inside a lithium battery. Their needle-like projections are called whiskers which can pierce the separator inside a battery leading to a short circuit or a fire. Dendrites also increase unwanted reactions between the electrolyte and the lithium, which eventually leads to premature battery failure.

Previous attempts to develop a solid-state separator capable of working with lithium metal at high rates of power generally required compromising other aspects of the battery cell, such as cycle life, operating temperature, safety, cathode loading, or excess lithium in the anode, QuantumScape said. The company's engineers addressed these issues with its latest solid state separator. 

QuantumScape's Partnership with Automaker Volkswagen

QuantumScape holds over 200 patents and patent applications related to solid-state battery technology. The company aims to commercialize its solid-state battery technology for the automotive industry as it pivots towards electrification.

In June 2018, Volkswagen invested $100 million in a joint venture with QuantumScape for the industrial-level production of solid-state batteries. At the time, Volkswagen said it successfully tested QuantumScape's early-stage solid-state battery sample cells running at "automotive rates of power", which the automaker said was an "industry first" achievement.

Volkswagen followed up its initial investment in June of this year with an additional investment commitment of up to $200 million, two months before QuantumScape announced its intent to go public in a merger with Kensington Capital. 

The goal of the investment was to further develop solid-state batteries for Volkswagen's future electric vehicles.The automaker plans to build millions of EVs over the next decade and will need a stable supply of low cost, high-quality batteries.

Last month, QuantumScape completed a reverse merger deal with Kensington Capital Acquisition Corp.(NYSE: KCAC), a special purpose acquisition company (SPAC). The deal, which was first announced in September, resulted in QuantumScape becoming a publicly listed company, which aims for an enterprise value of over $3 billion.

QuantumScape's board members include JB Straubel, Co-founder Tesla, Jürgen Leohold, Former Head of Volkswagen Group Research, and Frank Blome, Head of Volkswagen Battery Center of Excellence.

QuantumScape is also backed by Microsoft founded Bill Gates, both personally and through his company Breakthrough Energy Ventures, a venture capital firm that Gates founded in 2015 to help accelerate innovations in sustainable energy. 

Funds from the company's recent IPO will support the company through the start of production planned in the second half of 2024.

QuantumScape's stock is trading on the New York Stock Exchange under the ticker symbol "QS". 

Eric Walz

Originally hailing from New Jersey, Eric is a automotive & technology reporter covering the high-tech industry here in Silicon Valley. He has over 15 years of automotive experience and a bachelors degree in computer science. These skills, combined with technical writing and news reporting, allows him to fully understand and identify new and innovative technologies in the auto industry and beyond. He has worked at Uber on self-driving cars and as a technical writer, helping people to understand and work with technology.