Salt-based battery | ALTECH & Fraunhofer Institute

ALTECH and the Fraunhofer Institute present an innovative salt-based battery that uses salt and ceramics.

The Altech Group is working with the Fraunhofer Institute for Ceramic Technologies and Systems (IKTS) to commercialise a salt-based battery. Uwe Ahrens, Managing Director of Altech Batteries GmbH and board member of Altech Advanced Materials AG, explains in an interview with ingenieur.de how the innovative ceramic solid-state battery based on table salt works.

• What is the goal of ALTECH and the Fraunhofer Institute in producing solid-state batteries?

Ahrens: Our goal is clearly defined: we want to bring a ceramic solid-state battery based on table salt onto the market under the name Cerenergy® as quickly as possible. To this end, the Altech Group, which includes the two listed parent companies Altech Batteries Limited (Australia) and Altech Advanced Materials AG (Germany), founded Altech Batteries GmbH together with the Fraunhofer-Gesellschaft in Munich. In a first expansion stage, the fully developed battery is to be produced in a plant with a capacity of 100 MWh per year in Schwarze Pumpe (Saxony). A detailed feasibility study is currently being prepared for this. We have already acquired the site, and the detailed engineering of the production plant is progressing well. We have a tight schedule so that we can begin the overall investment this year. The aim is to ensure market entry with this first line as soon as possible and then drive further expansion into the gigawatt range.

Potential of solid-state batteries

• What is the main difference between solid-state batteries and lithium-ion batteries?

Ahrens: A Cerenergy® battery contains no lithium, no cobalt, no graphite and no copper, but primarily only sodium and aluminium oxide (ceramic). Both are substances that are available locally and can be supplied through environmentally friendly and responsible supply chains. A Cerenergy® battery consists of a ceramic tube, the solid electrolyte (conductive for sodium ions), with a positive collector in the middle. The solid ceramic tube performs the same function as a liquid electrolyte in a lithium-ion battery by allowing the bidirectional transfer of sodium ions through the ceramic tube. This solid electrolyte and the absence of a graphite anode prevent any loss of sodium ions. This is quite the opposite of lithium-ion batteries, in which lithium ions are lost and the battery’s capacity therefore keeps falling over its lifetime. The ceramic tube of the Cerenergy® is filled with a cathode granulate that, besides table salt, contains other additives that are part of Altech Batteries’ IP and know-how.

Difference from lithium-ion batteries

• What potential do solid-state batteries have compared with other battery technologies, and what advantages do they offer?

Ahrens: These batteries have a large number of significant advantages in manufacture and use. First, there is temperature-independent use. Without external cooling or heating, the battery can be used without voltage losses in a range between -20 °C and +60 °C. This not only extends the geographical range of use but also significantly reduces running costs, since there is no need for temperature management by air conditioning. The batteries are therefore also completely silent.

Unlike today’s lithium-ion batteries, Cerenergy® batteries are not flammable. No thermal chain reaction can occur, as the battery contains no flammable materials. The main component of the batteries is obtained from ordinary table salt. This greatly increases the range of applications: the batteries can be operated completely safely in buildings and halls. No safety distances have to be observed, and the batteries can also be stacked safely. None of this is possible with conventional lithium-ion batteries. They contain a liquid flammable electrolyte and a flammable plastic separator and, as is well known, are practically impossible to extinguish once a chemical chain reaction that produces oxygen has been triggered.

Cerenergy® batteries practically do not age and retain their full charging capacity over their entire lifetime of more than 15 years.

• What advantages do the solid-state batteries from ALTECH and the Fraunhofer Institute have, especially with regard to their longer service life?

Ahrens: Depending on the application, the service life of lithium-ion batteries is limited to 7–10 years and often less. Their performance deteriorates with every charge and discharge cycle. These losses are often due to harmful side reactions such as dendrite growth, lithium loss as a result of interface layer formation on the anode, and other reactions in the electrolyte as well as in the cathode structures. These negative effects occur much faster when the battery is operated quickly (high C-rate) and frequently (> once a day) or outside the ideal temperature range, which is very often the case. The MegaPack of a well-known manufacturer, for example, guarantees one charge-discharge cycle per day. With Cerenergy® we manage three a day.

In contrast, the service life of Cerenergy® batteries is at least 15 years without any significant loss of performance.

The biggest advantage is that they are practically maintenance-free. You connect the batteries and that’s it: plug and play. Since there is no mechanical fan, operation works without air conditioning and the battery cells are harmless and therefore do not need to be monitored, controlled or replaced, the operating costs of our Cerenergy® are significantly lower than those of a lithium-ion battery. We expect cycle costs of 5 cents and less.

Fundamentally, performance must be increased considerably and the use of resources significantly reduced.

Uwe Ahrens

Managing Director ALTECH Batteries GmbH

Interested? Find the whole interview on ingenieur.de and read on there.

Read more (German)