Solid-state batteries with bi-layer cell design

Image: Ion Storage Systems

Ion Storage System’s $30 million capital raising will go toward scaling up its solid-state battery cell production facility in the US state of Maryland, with aims to produce 10 MWh per year by the end of 2023, for a range of applications.

From pv magazine

Ion Storage Systems, a US battery startup based in Maryland, has received $30 million in Series A venture capital funding from the likes of Toyota Ventures, Tenaska, and Bangchak Corp. The company aims to develop factories to reach mass battery cell production.

Ion Storage is developing solid-state batteries and aims to produce 10 MWh per year and generate commercial revenue by the end of 2023. The key differences to other solid-state and next-generation batteries is a bi-layer cell design. This reduces typical lithium-ion battery defects, and works with existing and next-generation cathode chemistries, avoiding the use of critical raw materials like cobalt, nickel, and gold.

Neil Ovadia, Ion’s vice-president of operations, told pv magazine that the company can target multiple markets, ranging from defense to consumer products to electric vehicles and stationary grid storage. Ovadia noted that Ion is working on a variation to the core product meant for stationary storage applications.

“Ion’s unique technology unlocks the power of solid-state batteries through its patented Bi-layer cell design. The dense ceramic electrolyte separator is connected to a porous ceramic electrolyte scaffold,” explained Ovadia. “The porous scaffold acts as a “sponge,” creating uniform and continuous pathways for lithium metal plating without external volume change, while the dense layer acts as a solid-state separator blocking lithium metal dendrites – thereby avoiding the need for compression and preventing short circuits. This architecture makes Ion’s solid-state electrolyte compatible with a wide range of existing and next-generation cathode chemistries.”

Ovadia further detailed the non-flammable materials used in the battery cell architecture.

“Ion bi-layer cell architecture is made of inexpensive, nonflammable materials and use of a lithium metal anode has been able to meet next-generation performance metrics, including high-energy density, strong cycling performance, wide temperature range, and fast charging all at room temperature and without compression,” he said.  “Its ability to utilize both existing and next generation cathode chemistries removes the need for supply constrained materials such as nickel and cobalt. The manufacturability of ION’s technology also sets us apart as we utilize already-scaled processing and high-speed green body manufacturing techniques for our ceramic electrolyte and largely utilize existing lithium-ion manufacturing processes for cell production.”

Furthermore, the battery allows for a “cathode agnostic” approach, opening a wide range of cathode materials to be used, he said.

Ion has previously said it aims to produce more than 1 million cellphone-size batteries annually, And while those figures were not restated, the plan is to develop Ion’s pilot manufacturing facility at its Beltsville headquarters in 2023. It will then supply samples to interested parties and first market customers.

In terms of the struggles that companies face to scale-up production processes, Ion says it “employs existing industrial scale ceramic preparation methods.” It claims its unique structure “allows for the use of widely deployed Li-Ion battery manufacturing equipment for final cell assembly.”  

Author: Tristan Rayner

Water-based zinc-ion battery for stationary energy storage

Residential energy storage. Image: Salient Energy

Salient Energy developed the water-based zinc-ion battery to have the same power, performance, and footprint as lithium-ion systems without the safety risk.

From pv magazine USA

Lithium-ion batteries dominate the market for electric vehicles and home energy storage due to lower cost, higher performance, and lower weight compared some alternatives, but the main challenges are safety and sourcing of materials. The safety risk of lithium ion is thermal instability, a condition that can lead to a thermal runaway.

Over the past several years lithium-ion batteries have been known to explode in laptops, cell phones, and to cause fires in large energy-storage facilities. Sourcing of the battery materials, which include lithium, cobalt, nickel, and graphite, is also a challenge as the materials often come from conflict-prone areas like the Congo. These challenges have led some manufacturers to seek alternatives. pv magazine USA spoke with Ryan Brown, CEO and co-founder of Salient Energy, a manufacturer of zinc-ion batteries, and he explained that Salient’s mission is to develop a battery that mimics the performance of lithium-ion while using abundant materials that come from conflict-free areas, and that do not pose a safety risk.

Brown acknowledged that lithium-ion is the best at energy for the weight and that manufacturers have done well to reduce cost, but safety remains an issue. He said, for example, recent fires in Tesla vehicles are caused by thermal runaway in lithium-ion batteries. “When used in home energy systems, safety is also a top priority,” Brown said.

Zinc-ion batteries are a non-flammable option, due to their water-based chemistry, Brown noted. He said that the zinc-ion energy storage systems have the same power, performance, and footprint as lithium-ion systems, “so they are a true alternative to lithium-ion.”

One advantage to zinc-based batteries is that they can be manufactured on the same lines as lithium-ion, which keeps manufacturing costs low. As far as safety goes, “safety is the killer advantage,” said Brown. “What we’ve done is we’ve made a zinc battery that works the same way lithium ion works. We have zinc reacting on both sides, so we don’t have to store the reactant in electrolyte.”

Target market

The main application market that Salient is targeting is stationary energy storage. “Residential yes, but ultimately we want to be in the shipping containers.” With the main advantage being safety, Brown sees the zinc-ion battery as a viable alternative for batteries that need to be placed indoors, such as in apartment buildings. “A city is not place to put energy storage outdoors, and with California mandating that apartments must have energy storage, zinc-ion is a safe solution.”

To demonstrate the safety of zinc-ion batteries as a residential energy storage solution, Salient Energy is partnering with Horton World Solutions (HWS) a sustainable homebuilder that is installing the batteries in 200K homes that it is constructing in the Dallas Fort Worth area as well as across the Sunbelt. Construction on these homes will be underway by Q4 of 2022.

Domestic supply chain

Salient’s batteries are made up of a zinc, a pH-neutral zinc sulphate electrolyte, and a manganese oxide-based cathode, all of which are abundant are mined and processed in North America, allowing Salient to source materials from a domestic supply chain. While Salient is based in Nova Scotia, in early 2022 the company opened an office in Oakland, Calif. A team of 7 engineers based in Oakland are currently focused on developing and improving Salient’s residential battery systems, the same system used in the HWS demonstration.

For now, Salient is manufacturing batteries at its Dartmouth, Nova Scotia facility at a small scale of around 100 batteries per month, but the company is in the process of ramping up production at this facility to the pilot scale (1000s of batteries per month) to support pilot projects in the residential space.

Author: Anna Fischer

Powering EV charging stations with agrivoltaics

Image: wikimedia commons

US researchers find that placing agrivoltaic installations along highways to power EV charging stations can reduce both carbon emissions and range anxiety.

From pv magazine USA

A research team from Oregon State studied the potential of agricultural land to generate solar electricity to power electric vehicles along the state’s highways. They found that agrivoltaic systems placed in adjacent proximity to the highway can be useful in rural areas, which is also where electric charging stations are most needed.

The study, recently published in Scientific Reports, looked at how agrivoltaic technology can be used to improve EV charging infrastructure to reduce range anxiety, which is the worry about making it to the next charging point.  In their analysis, the team envisioned a scenario that had the highest traffic demand and the lowest photovoltaic generation, and the results showed that agrivoltaics could play a role in charging station infrastructure development.

In the study, a total of 231 rural highway access points were identified that had sufficient land area to service EV charging stations with energy generated by agrivoltaic installations. These areas are indicated with black circles Figure 1.

Model results with distribution and quantity of highway access points serviceable by agrivoltaic systems, highway access points not serviceable by agrivoltaic systems, land supply available, and the portion of land supply needed to meet electricity demand at serviceable highway access points. Image: Oregon State University, scientific reports, Creative Commons License CC BY 4.0

The team discovered that to meet the conservative estimate of EV charging station demand at 86% of highway access points through Oregon, 12,000 acres (18.75 square miles) of land would be required. Of the 231 highway access points identified for agrivoltaics, 220 (95%) have a distance between them that is less than 17 miles. The researchers looked at earlier research conducted in Croatia that indicated that people have less range anxiety if charging stations are less than 3.1 miles apart. And other research shows that gas stations tend to be 2.5 to 18 miles apart. The Oregon State team used this range as a basis in their scenario.

Based on the number of vehicles registered in the state of Oregon and how much carbon they emit each year, the team estimated that the potential for carbon reduction through agrivoltaic-powered EV charging stations is about 3.1 million tons or the equivalent to 673,915 vehicles removed from the road each year, if their approach were fully implemented.

Overall the Oregon researchers showed that servicing rural EV charging stations with agrivoltaics next to the highway is feasible, requiring only 3% of total land supply to power 86% of rural highway access points throughout the state.

As rural areas often lack the grid infrastructure to support charging stations, agrivoltaics enable the shift in energy production to the point of use. Oregon currently has 670 EV charging stations, and the researchers’ scenario adds another 231 charge points located in close enough proximity to reduce or eliminate range anxiety. Additionally, the team estimates that implementation of this approach could reduce annual carbon emissions from passenger vehicle use in Oregon by 21%.

Author: Anne Fischer

Glass pyramid concentrator for solar cell applications

Image: Stanford University, Nina Vaidya

Stanford University scientists have built an optical concentrator that purportedly harvests more than 90% of the light that hits its surface.

From pv magazine

Researchers at Stanford University have created a glass pyramid optical concentrator that concentrates light on solar cells, regardless of the light incidence angle.

“It’s a completely passive system – it doesn’t need energy to track the source or have any moving parts,” said research coordinator Nina Vaidya. “Without optical focus that moves positions or need for tracking systems, concentrating light becomes much simpler.”

The AGILE (Axially Graded Index LEns) device purportedly harvests more than 90% of the light that hits its surface. It also creates spots at the output that are three times brighter than the incoming light.

“Installed in a layer on top of solar cells, they could make solar arrays more efficient and capture not only direct sunlight, but also diffuse light that has been scattered by the Earth’s atmosphere, weather, and seasons,” the scientists explained, noting that the solar cell could be built with fewer raw materials and at lower costs.

They said a top layer of the concentrator could be used to replace existing encapsulation materials. That would in turn create space for cooling and circuitry to run between the narrowing pyramids of the individual devices. The pyramid was made of different optical glass flats provided by Japan’s Ohara Corp.

“The geometry of the pyramid was a square of side 14.5 mm down to a square of 8.5 mm giving a concentration of three, along a total height of 8 mm with 8 glass layers, with each flat 1 mm thick,” the academics said.

They layered the glass together with polymers that bend light to different degrees. “The layers change the light’s direction in steps instead of a smooth curve,” they said. “The sides of the prototypes are mirrored, so any light going in the wrong direction is bounced back towards the output.”

The prototype can improve optical concentration by a factor of three and achieve a 90% efficiency in capturing light, they claimed in “Immersion graded index optics: theory, design, and prototypes, which was recently published in Microsystems and Nanoengineering.

“Results of the functional prototypes demonstrate that immersion graded index technology can improve the way we concentrate and couple light many fold,” the scientists said. “The AGILE has the potential to greatly improve opto-electronic systems by reducing cost, increasing efficiency, providing a scalable concentration system with built-in anti-reflection and encapsulation without the need for tracking.”

Author: Emiliano Bellini

Single-axis trackers on commercial rooftops increase generation by 37%

Image: Alion Energy

Alion Energy trackers thread the return-on-investment needle with productivity gains from white roofs and bifacial modules, while design aggressively maximizes module count.

From pv magazine USA

Alion Energy’s single-axis tracker racking product was originally designed to be deployed in regions where heavy installation equipment was more challenging to access, but labor might be more available.

One aspect of this design philosophy is that the system is light and can be easily carried and assembled, and doesn’t require metal pilings to be driven deep into the ground. And interestingly, this carries over to commercial rooftops.

Mark Kingsley, Alion Energy CEO, said in a post on LinkedIn that a commercial real estate group had installed a standard rooftop, 10-degree fixed tilt monofacial solar array, as well as a competing Alion Energy system.

The results were as expected – 37.5% greater generation on a per watt basis from the single-axis tracker, on a pristine white thermoplastic roof versus standard modules. Of course, the real breakthrough is that they were able to get single-axis trackers installed on a commercial rooftop at all.

The rooftop in their example has a lot of skylights, and the overall structure is not facing due south. In this configuration, Alion Energy suggests that it can fit 4.55 MW of modules on the Maryland structure with a standard 10-degree installation. This system is projected to generate 1.34 kWh per watt each year.

Alion has designed a system that is 5.4 MW – a full 18% increase in wattage due to systems ability to be installed directly over skylights without needing the standard setback. Additionally, this hardware is projected to generate 1.54 kWh per watt installed per year.

In this case, that works out to 37% more electricity from the same rooftop. And when the trackers are directly attached to the roof – a 2.15 pounds per square foot dead load. Add in one Alion’s customized robotic cleaners, and the company says the levelized cost of electricity from the system falls to 4.67¢/kWh and generates 40% more electricity than a standard rooftop solar install.

And while this rooftop was selected to show off their hardware, it’s still an interesting best case scenario for us to consider.

Author: John Fitzgerald Weaver

US lab reveals top findings for hybrid solar, storage plants

Image: Sharp

US government researchers have collected 10 observations from recent research papers that look at solar- or wind-plus-storage power plants in the United States.

From pv magazine USA

The US Department of Energy’s Lawrence Berkeley National Laboratory (LBNL) has released a top 10 list of observations on co-located wind or solar-plus-storage (hybrid) projects.

LBNL is covering the topic due to rising deployment and interest in such hybrid facilities. Assuming that future project queues can be used to predict the number of actual hybrid power projects that will get built, hybrid systems already make up 42% of the future US potential for 675 GW of solar generation capacity. California’s solar queue, for all intents and purposes, is a solar-plus-storage queue, with its 95% coupling rate.

As of the end of 2021, 5.9 GW of solar was coupled with energy storage, along with 750 MW of wind-plus-solar-plus-storage. LBNL noted the exponential growth of this type of capacity, which is up 133% since the end of 2020.

The fundamental reason that solar-plus-storage works is that the price of batteries has come down to a point where it now makes financial sense. Battery pricing has declined by roughly 25%, from $40/MWh to $95/MWh of PV in 2017, to $30/MWh to $75/MWh of PV in 2021.

Second, and more importantly, LBNL modeled the revenues versus the costs of adding batteries to solar. They found that the value gained by adding energy storage to solar and wind exceeds the costs.

Taking into account the battery inverter versus solar plant inverter size, LBNL found that adding four hours of energy storage to a power purchase agreement (PPA) increased the price of that agreement pretty linearly. Considering the most popular ratio of solar vs. battery inverter capacities – 1 MW solar to 0.5 MW batteries providing four hours of storage – the addition of energy storage increases PPAs by $0.01/kWh.

LBNL also sees that there are financial penalties associated with the current techniques of coupling solar with energy storage. For instance, if the solar power is fully using the site’s interconnection at any point, the batteries cannot. Also, if the batteries must fully charge from the onsite solar to meet incentive requirements, that can be a penalty for hybrid systems, resulting in a slightly less financially efficient system.

In terms of financial incentives, the Federal Investment Tax Credit seems to be motivating hybridization. Without this incentive, it is believed that there would be more standalone energy storage.

Since California dominates the volumes of hybrid solar plants in the queues, it also heavily influences the averages. Leaving California’s four-hour heavy market (which is at least partially driven by an evening peak period that lasts four to five hours), the researchers found that California’s batteries tend to have shorter durations in most other markets.

The chart above models the value of energy being delivered by hybrid systems as more battery duration – from two to eight hours – is added to a facility in various power grid regions around the nation.

There is still a lot of learning going on with these technologies. For instance, a 100 MW solar farm plus a 50 MW battery does not equal a 150 MW power plant in terms of capability. Having an intermittent, highly predictable solar generation resource, coupled with an instantly dispatchable multi-talented re-generation battery resource means that sometimes interconnection must be shared – and it’s usually the battery that takes a backseat to the solar facility during generation periods.

This is the hybrid penalization referenced earlier. Asset owners and markets are still learning how to maximize the utilization of these resources.

The document notes that the ancillary service markets provide valuable revenue streams to this young battery market, but that this service market quickly sells out. These large scale markets of independent system operators – where wholesale electricity rates and ancillary services exist – are not where most batteries are earning their revenue these days.

LBNL said that by the end of 2020, most operating hybrids earned revenue via incentive programs or capacity and transmission demand charge markets, instead of wholesale market price signals.

For instance, a battery used for peak shaving behind the meter at a business, or to maximize onsite solar utilization, does little for the broader wholesale market – although they do offer some general peak demand reduction. A battery at a home only running during power outages offers far less than a peak shaving solution; however, some VPPs are beginning to step into this space to monetize these underutilized resources.

We’re also observing a separation of attachment rates, as residential solar-plus-storage is growing faster than small business, commercial, and industrial. LBNL has also observed that residential energy storage solutions are getting larger.

This split – where residential storage is surpassing commercial and industrial storage – is mirrored by residential solar as well, as it outpaces business, commercial, and industrial solar in terms of capacity deployed annually.

Author: John Fitzgerald Weaver

Wireless EV charging coming soon to US market

Source: WiTricity

From pv magazine

Electric vehicle owners may soon be able to simply park and charge, no wires needed, with a new product under development from WiTricity.

The company has announced a limited beta release of its Halo wireless charging station this year, with wider availability in 2023. WiTricity has already been providing EV automakers with factory-installed EV wireless charging tech, and it now plans to make a consumer-level aftermarket product.

The Halo system can deliver 11kW of wireless charging. It consists of three key components, including a power receiver installed on the vehicle, a wall box that connects to wired power, and a charging pad installed on (or in) the ground.

The system uses core magnetic resonance charging to power EVs. WiTricity’s charging system, peripheral systems, and controlling software have been awarded more than 1,200 patents. The technology is has been instrumental in developing global wireless charging standards, including SAE International, International Organization for Standardization (ISO), the International Electrotechnical Commission (IEC), and the Standardization Administration of the People’s Republic of China (GB).

A pilot Tesla Model 3 has been running fully on wireless charging in Watertown, Massachusetts, since October. The vehicle can be fully charged in less than six hours, which is just as fast as plugging in at home. 

“Our successful upgrade of the Tesla Model 3 is resonating with consumers as an easier, more convenient way to charge their EVs,” said WiTricity CEO Alex Gruzen. “With the WiTricity Halo solution you just park and walk away, knowing you will return to a fully charged car. Day to day, it’s as if your car had infinite range, which will help accelerate EV adoption and propel us to a greener future.”

The company said it is currently evaluating which models to offer wireless upgrades for, based on customer demand, technical feasibility, and automaker support. Companies interested in the beta program can follow on the WiTricity website.

Author: Ryan Kennedy