In the first move to reduce greenhouse gas emissions of its ground operations, United Airlines (UA, Chicago O'Hare) is investing an undisclosed sum in California-based Natron Energy, a battery manufacturer whose sodium-ion batteries could help the airline electrify its airport ground equipment like pushback tractors and gate operations.

Natron plans to use the funds to accelerate production at its manufacturing facility in Holland, Michigan, where it will scale operations to begin mass production of Underwriters Laboratories (UL)-listed sodium-ion batteries in 2023, the parties said in a joint statement.

Apart from a better output and cycle life than their lithium counterparts, sodium-ion batteries are nonflammable, a critical safeguard for the high usage and power that would be required for certain operations. The minerals used in sodium-ion batteries are abundant worldwide and are easily sourced, unlike lithium which is in short supply with demand expected to triple by 2025.

United Airlines has more than 12,000 pieces of motorised ground equipment across its operations, of which about one-third are currently electric. Natron's batteries could potentially be deployed in support of a number of uses, including:

  • Charging electric ground equipment;
  • Charging anticipated future electric aircraft such as electric air taxis;
  • Allowing airport operations to manage electricity demand; and
  • Improving resiliency related to inclement weather.

Through United Airlines Ventures (UAV), the venture capital arm of parent United Airlines Holdings, the airline already has made several investments in green technology in support of its goal of net zero emissions by 2050. UAV's portfolio now includes Sustainable Aviation Fuel (SAF) producers and other technologies, including carbon utilisation, hydrogen-electric engines, electric regional aircraft, and urban air mobility.

"Out of the gate, we primarily focused on technology designed to help reduce carbon emissions from our airplanes. Natron's cutting-edge sodium-ion batteries presented an ideal opportunity to both potentially expand our sustainability investment portfolio to our ground operations, and to help make our airport operations more resilient," commented UAV president Michael Leskinen.