QuantumScape’s technology is based on a solid-state battery that uses an anode-free lithium-metal cell design. The company is developing solid-state batteries for electric vehicles, expected to offer faster charging, longer range, higher energy density, and better safety than conventional lithium-ion batteries.

QuantumScape’s technology means that the battery does not have separate anode materials, but instead uses pure lithium metal as the anode during charging and discharging. It also eliminates the need for graphite or other anode materials, taking up space and weight in the battery.

It also reduces the risk of dendrites, which are needle-like structures that can grow on the anode and cause short circuits or fires. However, using lithium metal as the anode also poses a major challenge: finding a suitable electrolyte that can conduct lithium ions between the anode and the cathode while preventing the formation of dendrites and maintaining the stability and integrity of the battery.

Most conventional electrolytes are liquid or gel-based, which are not compatible with lithium metal and can cause leakage, corrosion, or degradation. The key innovation of the company is a separator made of a proprietary flexible ceramic material that resists dendrites and can’t catch fire.

The separator acts as a solid electrolyte that allows lithium ions to pass through while blocking electrons and other unwanted substances. The separator also forms a thin layer of lithium metal on its surface, which serves as the anode during charging and discharging.

The separator is sandwiched between a cathode made of nickel-manganese-cobalt oxide (NMC) and a metallic current collector. QuantumScape claims that its battery can charge to 80% of capacity in 15 minutes, retain more than 80% of capacity after 800 cycles, and have a volumetric energy density of more than 1,000 watt-hours per liter.

This would make it superior to current lithium-ion batteries, which typically charge to 80% of capacity in 30 to 60 minutes, retain 80% of capacity after 300 to 500 cycles, and have a volumetric energy density of 60 to 700 watt-hours per liter.

For over a decade, QuantumScape has been working in collaboration with Stanford University and Volkswagen Group, its largest shareholder and strategic partner.

The company also received funding from other investors such as Bill Gates, Khosla Venture, and Breakthrough Energy Ventures. The company went public in 2020 through a merger with a special purpose acquisition company (SPAC), raising $1.5 billion and reaching a valuation of more than $20 billion.

In 2021, it demonstrated its single-layer cell that completed 400 consecutive 15-minute fast-charge cycles, replenishing from 10% to 80% capacity while still retaining over 80% of its initial energy. It also revealed its 10-layer cell, which is closer to the commercial size and performance.

In 2022, it delivered its first 24-layer cell prototypes to EV automakers for them to test and validate.

Nevertheless, nothing comes without its fair share of challenges and uncertainties. One of the challenges is to scale up its production and reduce its costs, which are currently unknown.

The company is planning to build its own pilot production line, called QS-0, which is expected to have an annual capacity of 100 megawatt-hours by 2023. It also plans to build a joint venture factory with Volkswagen, called QS-1, which is expected to have an annual capacity of 1 gigawatt-hour by 2024 and 20 gigawatt-hours by 2028.

Another major challenge that every company is going through is its ability to prove the reliability and safety of its battery technology in real-world conditions and applications, which are different from laboratory tests and simulations.

However, it is not that QuantumScape is the ultimate battery developer for electric vehicles, which could revolutionize the EV industry and the clean energy sector. It still has a long and uncertain road ahead.

The failure and success of QuantumScape have a significant impact on the future of batteries, EVs, and the environment.

Sources:- wired, QuantumScape, electrek, the verge, bloomberg, cnbc, electrek