Explained: Breakthrough in battery technology


Shareholders of California-based QuantumScape Corp, a battery start-up backed by Volkswagen AG, approved a multibillion-dollar salary package for chief executive Jagdeep Singh, who could potentially receive stock options. valued at $ 2.3 billion, subject to the company meeting certain performance milestones. .

The announcement sparked comparisons to the package Tesla awarded to Elon Musk in 2018, and highlighted the potential of this nascent industry, some of which have yet to bring a product to market.

A quantum leap

QuantumScape’s solid-state battery – lithium metal with a solid electrolyte separating the two electrodes – is seen as an unusually bright prospect in an increasingly crowded space. The company, which was co-founded by Singh a decade ago and received financial backing from Volkswagen and the Bill Gates venture capital fund, publicly traded late last year and valued at nearly $ 50 billion in a few months on the promise that its new battery technology could provide a safer, cheaper alternative to lithium-ion batteries.

Previous efforts to build a solid state (electrolyte) separator capable of working with lithium metal had to compromise on aspects such as battery life and operating temperature, and the problem of deposits. excessive lithium on the anode. QuantumScape claims to have circumvented this: Its use of solid state separation technology eliminates the side reaction between liquid electrolyte and carbon / graphite in the anode of conventional lithium-ion cells.

An employee holds a QuantumScapes solid-state lithium metal battery for electric vehicles in San Jose, Calif. On February 4, 2021. The company is working on technology that could make car batteries cheaper, more reliable, and faster to use. reload. (Gabriela Hasbun / The New York Times)

Volkswagen plans to start production of solid-state batteries by 2025 through the partnership with QuantumScape.

Semiconductor batteries

The energy density of lithium-ion cells used in cell phones and electric vehicles today is almost four times that of older generation nickel-cadmium batteries. Lithium-ion batteries use aqueous electrolyte solutions, where ions move between the anode (negative electrode usually made of graphite) and the cathode (positive lithium electrode), triggering the recharging and discharging of electrons. Despite technological improvements over the past decade, problems such as long charging times and low energy density persist. While lithium-ion batteries are considered efficient enough for phones and laptops, they still lack the reach that would make electric vehicles a viable alternative to internal combustion engines.

A major problem is that lithium metal is extremely reactive. The main form of lithium corrosion is dendrites, which are branched lithium structures that grow from the electrode and can potentially pierce through the separator and at the other end, bypassing the cell. In current lithium-ion batteries, the electrolyte of which is a flammable liquid, the formation of dendrites can start a fire.

Jagdeep Singh, CEO of QuantumScape, in San Jose, Calif., February 4, 2021. The company is working on technology that could make car batteries cheaper, more reliable, and faster to recharge. (Gabriela Hasbun / The New York Times)

QuantumScape says its lithium-metal solid-state battery replaces the polymer separator used in conventional lithium-ion batteries with a solid-state separator. The replacement of the separator allows the use of a lithium-metal anode instead of the traditional one
carbon / graphite anode.

The lithium metal anode is more energy dense than conventional anodes, allowing the battery to store more energy in the same volume, according to the company. The QuantumScape design is intended to be “anodeless” since the battery is manufactured in a discharged state and the negative electrode forms in situ on first charge.

Key Benefits

The advantages of solid-state battery technology include higher cellular energy density (by removing the carbon anode), shorter charge time (by eliminating the need to diffuse lithium into carbon particles in conventional lithium-ion cells), the ability to undertake more charge cycles and therefore a longer life and improved safety.

A lower cost could be a game-changer, given that at 30 percent of the total cost, battery expense is a key factor in vehicle costs.

A study from Deloitte has shown that the top three considerations for consumers buying an EV are price, reliability, and cost of charging. Lithium-ion battery costs are currently around $ 137 per kWh and are expected to reach $ 101 / kWh by 2023, according to data from BloombergNEF.

QuantumScape says it aims to reduce the cost of batteries by 15-20% compared to the cost of lithium-ion batteries in several years.
Others in the field

THE FORM ENERGY IRON-AIR BATTERY: In July, U.S. company Form Energy Inc. announced a rechargeable iron-air battery capable of delivering electricity for 100 hours at a system cost allegedly competitive with conventional power plants and less than a tenth the cost of the system. lithium-ion. The company said its battery at the front of the meter – a utility-scale or grid-wide storage battery that can be connected directly to a distribution or transmission grid or to utility-scale assets. power generation – can be used continuously to support 24 hour operations of a renewable power grid.

The battery exploits the concept of “reversible rust”: it uses oxygen from the air and converts metallic iron to rust when discharging, and when charging, the application of an electric current turns the rust into iron and the battery releases oxygen into the air.

However, the size and weight of the battery – each unit is the size of a small refrigerator – makes its application impractical in electric vehicles.

TOYOTA SOLID STATE BATTERY:
Toyota tops the list of some 1,000 global patents for solid-state batteries. The Japanese automaker is trying to take the lead from the Chinese, who are currently the leaders in Li-ion batteries. Toyota plans to be the first company to sell an electric vehicle equipped with a solid-state battery and is in the process of unveiling a prototype. Nissan is also in the fray.

APPLE BATTERY TECHNOLOGY:
In the last half of 2020, Apple Inc said it is advancing in self-driving car technology and is aiming for 2024 to produce a passenger vehicle.

At the heart of Apple’s strategy is a ‘revolutionary’ battery design that could ‘drastically’ reduce the cost of batteries and increase vehicle range, according to someone familiar with Apple’s battery design cited by Reuters.


TESLA BATTERY TABLES:
In September last year, Tesla unveiled plans to develop a new “tableless” lithium-ion battery that could improve the range and power of an electric car. A tab is the part of the battery that forms a connection between the cell and what it powers. Tesla says its cells without tables will give the company’s electric vehicle batteries five times the energy capacity, make them six times more powerful and allow a 16% increase in vehicle range.

INDIA’S BATTERY PUSHBUTTON

THE CENTER is working on a plan for an approximately 4,000 MWh grid-wide battery storage system project in regional load sharing centers that control the country’s electricity grid, primarily to balance the vagaries of the renewable energy production.

RELIANCE INDUSTRIES LTD has announced its intention to set up a Giga energy storage plant; State-owned NTPC Ltd has issued a global tender for a grid-scale battery storage project.

THE DEPARTMENT of Heavy Industries issued a request for proposal on October 22 this year for the establishment of manufacturing facilities for the storage of Advanced Chemistry Cell (ACC) batteries in India. The deadline for submitting proposals was December 31.

About Robert Pierson

Check Also

Electricity is expensive. Drivers shouldn’t pay for it

Comment this story Comment With the rush to adopt electric vehicles, charging networks are rolling …