Solid-State Batteries: Innovations, Promising Start-ups, Future Roadmap

As climate change concerns continue to drive interest in clean energy and our daily lives become increasingly digitized and dependent on electronics, electrification has become a widespread trend across almost every industry. The problem is that battery innovation hasn’t kept pace with the electric revolution. Charging time, available capacity, lifetime degradation, and costs are key performance areas that are lacking in batteries today.
While most efforts to enhance battery performance to date have been focused on battery chemistry, this has only led to incremental changes over the past 30 years. The key to the next step-change in battery performances lies within its structure.
This is what Addionics is doing - changing battery architecture to allow the next step-change in battery performance, to any battery chemistry, existing or emerging.

Today, battery performance is limited by active materials. Graphite storage ability is one of the bottlenecks we can solve using Silicon (Si). Our nanoSi and microSi are based on elemental Si; we call our materials REALSiTM, which is not an oxide, nor produced by Silane gas. Advano converts metallurgical Si, including scrap, into battery-grade REALSiTM using proprietary material science technology. REALSiTM offers tailor-made solutions to both solid-state and liquid-electrolyte batteries. We are open to partnerships to accelerate the commercialization of real Si. The next major evolution in batteries is real Si; our team envisions having REALSiTM in every battery.

The silicon nanowire anode technology addresses silicon swelling by enabling silicon to expand and contract internally, in a very robust mechanical structure. As a result, over 1200 Wh/L and 450 Wh/kg levels of energy density were achieved in lithium-ion cells with a cycle life in the hundreds of cycles and fast charging in under 10 minutes, enabling new devices and applications.

BlueSolutions has been commercializing all-solid state batteries since 2011. EVs, buses and stationary applications are the main targets of its research and development program. After more than 15 years, this Bolloré group subsidiary masters all the industrial processes for the production of a unique solid state battery technology. The know-how goes from the transformation of the lithium ingots to the integration of the battery packs within the applications. Importantly, a low-ecological footprint process has been stated for both the positive electrode and the polymer electrolyte manufacturing.
In order to get incomparable energy densities, today, all the industrial actors of lithium batteries are hardly working on the lithium metal technology. In this context, BlueSolutions has a unique 10 years feedback regarding both the behavior of this special anode and of the solid-state electrolyte.
After having spread the first pack generation for 8 years all-over the world, an optimized 650V battery pack addressing the e-buses market is being delivered for one year. To match with customers expectations this new generation offers optimized performance and a very long cyclability. In the meanwhile, BlueSolutions has already started working on its future generation products. While the current battery is LFP-based and cycles at a nominal temperature of 80°C, a lot of efforts are dedicated to improve the actual chemistry. Research programs are conducted on the development of a new positive electrode with higher energy density, new electrolytes that will be compatible with high-voltage materials and which have high conductivity at ambient temperature and optimized lithium electrode. In fine, the goal is to keep the intrinsic safety of the polymer solid electrolyte, while benefiting from the promising performances of new electrode materials.

Through a broad portfolio of advanced carbons that includes carbon nanotubes (CNT), carbon black (CB), and carbon nanostructures (CNS), Cabot Corp. has brought the world leading solutions of conductive carbons for lithium ion batteries (LIBs).

Cabot’s research and development team has worked to optimize the usage and function of conductive materials in LIBs. In cathodes, high aspect ratio CNTs, show clear benefits in imparting electronic conductivity at the lowest loadings across an electrode film. While, aciniform carbons, CBs, can make many contact points with lithium containing active materials for efficient ionic conductivity, as well as provide the space necessary for Li+ transport, while balancing the cost and processability challenges of CNTs. In silicon containing anodes, CNS is a new class of novel crosslinked CNT materials that greatly improve the cycle life of the cell. This has been shown through electrochemical testing of model cells.

Conductive carbons continue to be a key material technology in LIB. Cabot continues to work to optimize their function in LIBs with the goal of enabling LIB makers to develop winning cell designs by pushing developments in energy density and cycle life among others.

The cathode material gives a lithium-ion cell its decisive characteristics. It is therefore an important factor, especially with regard to the ever-increasing demands on energy density. We would like to show you which special parameters are important when choosing the right cathode material and we will go into the current trends and developments in this area. We will not only share information about the electrochemical characteristics but also examine challenges in processing, the cell design and the economic as well as ecologic components.

A major improvement for the next generation of Li-ion batteries is the introduction of silicon as material for the anode, bringing capacity and fast charging to the next level. The biggest challenge of applying silicon-dominant anodes in Li-ion batteries, is silicon's tendency to expand during cycling.

E-magy has invented and manufactures micron-sized silicon particles with nanopores that overcome this challenge by containing that expansion within the nanopores themselves. Li-ion batteries with anodes made of E-magy silicon hold 40% more energy than those made of graphite. It's the low-cost, drop-in solution compatible with existing production lines that the EV industry needs – as currently verified by R&D managers of more than a dozen leading automotive and battery manufacturer brands.

Solid-state batteries combining an alkali metal anode and a high-voltage cathode have the potential to double the energy density of current-generation rechargeable batteries. We recently demonstrated the integration of hydroborate solid electrolytes with a 4 V class cathode through in-situ formation of a passivating interface layer. Combined with their high ionic conductivity > 1 mS/cm at room temperature, low gravimetric density 1.2 g/cm3, low toxicity, high thermal and chemical stability, stability vs lithium and sodium metal, soft mechanical properties enabling cold pressing, compatibility with solution infiltration, and potential for low cost, hydroborate electrolytes represent a promising option for a competitive next-generation solid-state battery technology.

Why bother with fast charge for EV batteries? Charge rate goes beyond driver convenience - it addresses core EV adoption issues such as addressing the fact that only 20% of cars have access to overnight charging, fast charging helps improve existing infrastructure utilization, and it supports drivers becoming more comfortable with less expensive vehicles that have shorter range lowering the price for those vehicles. Enevate is a battery technology company supplying breakthrough Extreme Fast Charge Technology with its pure silicon-dominant cells that are solving these crucial EV adoption issues.