Consistent access to energy is key for mission critical entities that bear the responsibility of enabling industrial and digital infrastructure to operate continuously. As battery technology has evolved to cater to the industrial-specific energy demands of power grids, data facilities, solar and wind farms, and others, the focus has shifted toward accelerating development in the areas of power, voltage, and capacity. While these features are highly valuable, they must be looked at as a secondary consideration, exceeded in priority by battery safety.
Safety features built into a battery cell, module, and rack can save mission critical entities millions of dollars in costs, downtime, and company losses. More importantly, they maintain consistency and minimize or mitigate potential damages that could disrupt energy access and create very challenging and even life-threatening scenarios.
New designs are being incorporated into industrial-grade batteries to enhance safety features, meet code requirements, and minimize environmental and health issues. But how do we define safety in such a critical industry, and what exactly makes a battery safe? And most importantly, how can industrial users ensure the cells, modules, and racks they’re using are suitable to reduce the risks that come from working with batteries?
From cradle to grave, industrial-grade lithium-ion batteries present significant safety concerns when not produced and handled with proper care. The top concerns can be divvied up into two separate categories: fire and worker safety.
Lithium-ion battery fires are typically the result of thermal runaway. Thermal runaway occurs when an electrochemical cell increases its temperature through self-heating in an uncontrollable fashion. During this process, the increase in temperature creates chain exothermic reactions that continue to generate a large amount of heat until it results in a fire. These reactions destroy the cell and can completely eliminate the battery module before the resulting fire spreads to surrounding cells, modules, and racks. Thermal runaway can be kickstarted by one of three main issues.
- Mechanical — Mechanical abuse is often defined as a physical impact that damages the cell, module, or rack. This can include a worker dropping the cell, a physical puncture, or any hard impact.
- Electrical — Electrical abuse is commonly attributed with charging and short-circuiting issues. This can range from internal or external short circuiting, abnormal charging forced discharge, or reverse charges.
- Thermal — Thermal abuse stems from heat. This can be an issue with the cell’s thermal stability or temperature cycling, or it can be the result of external high temperatures and overheating.
There are a number of factors that can trigger thermal runaway. While part of the process involves incorporating control measures to minimize the risk of enacting thermal runaway, other safety features need to be considered to minimize fire propagation in the event of battery thermal runaway.
Protecting workers from injury and harm is critical for an organization. Not only can injured workers create lag in productivity, but significant injuries or death can result in lawsuits, costing companies billions of dollars in finances and downtime. All of this can be damaging to corporate morale and can hinder recruiting efforts for top talent.
One of the main safety concerns stems from electrical shock that often occurs simply from working around high-voltage electrical equipment.
A report from the National Fire Protection Association (NFPA) that looked at the risk of death for laborers involved in electrical work cited that 80% of fatal injuries from direct exposure to electricity occurred while workers were engaged in constructing, repairing, or cleaning activities. Unsurprisingly, 37% of fatal injuries from indirect exposure were also from these same activities.
As the industry is moving toward large-scale energy storage systems, this often require laborers to work around high-voltage energized batteries and electrical equipment, putting them at higher risk of injury.
Battery weight can become a concern as the industry is focusing on increasing the energy density of batteries, which leads to heavier battery modules. Currently, the typical battery module weighs around 85 to 110 pounds — that becomes a heavy lift when hundreds of battery modules need to be physically handled during installation and decommission. As result, there’s a higher risk that employees could either injure themselves or accidently damage the battery modules.
There are a number of design elements that can reduce the risk of thermal runaway as well as features that minimize the risk of fire propagation. Battery module designs that balance heat dissipation and fire containment are essential to ensure safety and performance.
Battery modules are intended to minimize cell damage in events of mechanical abuses and reduce the risk of fire propagation. Forced-air cooling is incorporated into each module, with air channels to reduce the battery temperature. During operation, the battery management system is designed to closely monitor the battery’s operating status and take preventive measures when the system operates beyond its limit or when encountering faulty conditions.
The module or rack needs to act as self-contained unit, minimizing the risk of fire propagation between other modules or racks, which can result in massive fire.
All of these elements tie into the UL 1973 standard compliance to ensure battery safety.
Innovative battery designs aren’t just focused on the safety of the product, they are incorporating elements that support the overall health and well-being of workers.
In addition to integrating onboard screens to display module status, manufacturers have started to add better handles and grips within the design itself to simplify installation and removal. Use of appropriate installation tools, equipment, and procedures can reduce the risk of injury that could take employees off the job for days or weeks.
Battery designs for mission critical energy storage applications have far greater consequences than those created for commercial consumer use. Understanding the risks and carefully selecting the best battery for the application is important to protect mission critical operations and the lives that depend on them. It’s like they always say — safety first.