XL Batteries: Petrochemical Infrastructure for Renewable Energy Storage

The Quest for a Lithium-Ion Battery Alternative

Numerous materials – encompassing sulfur, sodium, manganese, and various organic molecules – have been investigated as potential replacements for the widely used lithium-ion battery. However, all previous attempts have ultimately proven unsuccessful.

The Challenge of Organic Batteries

Organic batteries, constructed from readily available elements like carbon, oxygen, and nitrogen, have presented a particularly frustrating challenge. They theoretically should offer a cost advantage over current batteries that rely on metals. Despite this potential, a viable organic battery solution has remained elusive.

That situation may be changing now.

XL Batteries' Innovative Approach

A nascent company, XL Batteries, is introducing a novel chemical approach that aims to surpass previous organic battery designs – and even lithium-ion batteries – in terms of cost-effectiveness, safety, and longevity.

“The initial capital expenditure should be exceptionally low,” explained Tom Sisto, co-founder and CEO of XL Batteries, in an interview with TechCrunch.

Focus on Grid-Scale Storage

The company’s technology isn’t immediately destined for use in the next generation of electric vehicles. The electrolyte utilized by XL Batteries for energy storage is more voluminous and heavier than those found in contemporary lithium-ion batteries. Consequently, the company is concentrating on grid-scale storage, where factors like scalability, cost, and safety are prioritized over weight and energy density.

The potential scale of XL Batteries’ installations is substantial.

Demonstration Unit at Stolthaven Terminals

XL Batteries has exclusively revealed to TechCrunch that it has commissioned a demonstration unit for Stolthaven Terminals, a specialist in petrochemical storage. This initial unit will be relatively small, but the company intends to rapidly scale up battery production once any operational issues are resolved, according to Sisto.

Leveraging Existing Infrastructure

A key factor contributing to Sisto’s optimism is the fact that a core component of the battery is essentially a standard storage tank.

“Utilizing just two of [Stolthaven’s] largest tanks would create a 700 megawatt-hour battery,” Sisto stated. This capacity is sufficient to power approximately 25,000 homes for a full day. “They possess 400 tanks at their Houston location.”

How Flow Batteries Work

XL Batteries is developing what are known as flow batteries. A fundamental flow battery comprises two tanks connected by pumps that circulate two fluids across a membrane. Charging the battery involves driving ions “uphill” – storing them within one of the fluids. Discharging releases electrons as the ions flow back across the membrane.

Addressing Limitations of Traditional Flow Batteries

Flow battery technology dates back to the late 19th century. However, their size and limited energy storage capacity hindered their widespread adoption. More recent advancements have improved energy storage, but these batteries often remain expensive due to the corrosive nature of the fluids used, requiring costly materials for pumps and other components.

The Elusive Organic Battery Breakthrough

While organic batteries have been proposed for some time, achieving a stable and lasting design has proven difficult. Most organic molecules, when overloaded with electrons, tend to decompose rapidly. Those that exhibit greater stability often require refrigeration and still degrade within a few months, Sisto noted.

A Novel Organic Compound

Recognizing the need for cost-effectiveness, Sisto sought a breakthrough during his research at Columbia University. He discovered an organic compound that established a new record for the highest number of electrons accepted by a single molecule. Initially, this molecule required suspension in a costly and flammable organic solvent. However, he and his team eventually stabilized it in pH-neutral water, paving the way for a viable business opportunity.

Modular Battery Design

A typical XL Batteries installation consists of a 40-foot shipping container and two storage tanks. The company’s proprietary membrane and other components are housed within the container, which is then connected to the storage tanks. The tanks determine the battery’s capacity, while the number of shipping containers dictates the charge and discharge rate.

Rapid Scalability

Due to the reliance on readily available technology, Sisto believes XL Batteries can quickly scale up production. “The commercial design is largely complete,” he said. The company is collaborating with an engineering firm experienced in flow battery design. “They already have the necessary components in place.”

Targeting the Texas Grid

Beyond initial customers like Stolthaven, XL Batteries is targeting independent power producers to deploy batteries supporting the grid, particularly in Texas, where such installations are becoming increasingly common.

“We are confident that the project-level economics are highly attractive,” Sisto concluded.