LFP, fire safety and life cycle: What to know before you communicate "green hardware"

Battery storage is often described as "green hardware". The phrase is easy to use, and it sounds right, because a battery helps make better use of solar and wind. But "green" is not a property that follows automatically from the battery chemistry. It is a claim about the product's full life cycle, from mining and manufacturing through operation to what happens to the system afterwards. And a claim of that kind must be documentable.

This article explains the difference between the two most common battery chemistries, LFP and NMC, why fire and safety belong in a sustainability assessment, and what is actually documented about production, transport and end-of-life. We also look at second life and recycling. The purpose is sober: to provide a basis so that a battery investment can be described honestly, without promising more about the hardware than can be substantiated.

LFP and NMC: two chemistries with different profiles

Most industrial batteries are based on lithium-ion technology, but the cathode, that is the positive electrode, can be made from different materials. Two chemistries dominate. LFP stands for lithium iron phosphate and uses iron and phosphate. NMC stands for nickel manganese cobalt and uses, among other things, nickel and cobalt.

The difference has practical consequences. NMC typically has higher energy density, meaning more stored energy per kilogram, which historically made the chemistry attractive in electric vehicles, where weight and space matter a great deal. LFP, by contrast, contains no cobalt, a material whose extraction is associated with both environmental and social problems, and LFP is more robust under frequent charge and discharge. On the other hand, LFP is less energy-dense, so it takes up more space and weighs more for the same amount of stored energy.

For stationary systems, where space is rarely the hardest constraint, that trade-off has clearly favoured LFP. In 2025, LFP accounted for around 90 percent of new battery storage capacity installed worldwide, compared with less than half five years earlier, precisely because the chemistry is typically cheaper and better suited to the frequent cycling a storage system is exposed to. The important point is that the choice of chemistry is not in itself a green or non-green choice. It is a technical trade-off between energy density, robustness, materials and safety.

Fire and safety as part of sustainability

Safety is rarely mentioned in the same breath as sustainability, but the two are linked. A system that is stable in operation and does not pose an unnecessary risk is a precondition for it to contribute positively over its lifetime at all. Here the two chemistries differ.

All lithium-ion batteries contain a flammable organic electrolyte, and in the event of a fault a so-called thermal runaway can occur: an exothermic chain reaction in which the cell generates heat and vents flammable gases. That applies regardless of chemistry. The difference lies in how easily and how violently it happens. Cell-level measurements show that NMC cells require substantially stricter safety design than LFP, and that a thermal runaway proceeds several times faster in NMC than in LFP. LFP is therefore considered more thermally stable. That is a real advantage, but it must be phrased precisely: more thermally stable does not mean that LFP cannot burn, only that the threshold is higher, and that an event is typically less violent.

Precisely because the risk exists regardless of chemistry, safe installation is regulated by codes and standards. For stationary systems there are internationally recognised standards for installation and product safety, including NFPA 855 and UL 9540, which set requirements for fire and smoke detection, fire suppression and enclosure. For an industrial company, the point is that operational safety is not something that sits beside sustainability. It is part of it. We cover production continuity and an unstable electricity grid in more detail in our overall guide to securing production.

The life cycle: production, transport and end-of-life

To assess whether hardware is "green", you have to look at the full life cycle, not only at operation. And here the picture becomes more nuanced than a single headline can hold.

Life cycle assessments, known as LCA, attempt to quantify environmental impact from cradle to grave. For electric vehicle batteries, such analyses typically indicate that LFP has a better overall environmental performance than NMC, while NMC in turn is more energy-efficient in the use phase and contains metals with higher recycling value. The most significant environmental burden comes to a large extent from extraction and processing of the metals in the cathode, which is part of the explanation for why cobalt- and nickel-free LFP often performs better overall.

But here is an important nuance. When you look specifically at stationary storage systems and not electric vehicles, the conclusion becomes less clear-cut. A cradle-to-grave analysis of stationary lithium-ion batteries over 20 years of operation could not unambiguously determine whether an LFP- or an NMC-based solution had the smallest environmental impact, because the result depends on the individual impact categories and on assumptions such as lifetime, efficiency and recycling at end-of-life. LFP therefore has a real footprint, and calling it green requires knowing and being able to document that footprint, not assuming it from the chemistry.

Transport and production belong in the picture as well. Batteries are heavy, production is energy-intensive, and the supply chain is global. Accordingly, EU rules require the life cycle to be documentable. The new Battery Regulation requires a carbon footprint declaration for industrial batteries above 2 kWh and introduces targets for collection, recycled content and a so-called battery passport, as well as due diligence requirements for the sourcing of lithium, cobalt and nickel among others. The regulation has been in force since February 2024, with a series of rules being phased in over the following years. The direction is clear: the environmental profile must be quantified and disclosed, not merely asserted.

Second life and recycling: opportunities with caveats

Two themes often appear when the life cycle is meant to look circular: second life and recycling. Both are real, but they should be described with caveats.

Second life covers the idea that a battery that is no longer suited to its original purpose, for example in an electric vehicle, can be used further in a less demanding stationary system. Research sees potential in reducing waste and supporting the use of renewable energy by giving spent batteries another application, but also points out that performance, economics and the real environmental gain depend on the battery's condition and operating conditions, and that the methods for assessing that are still under development. Second life is therefore a possibility, not a guarantee, and it says nothing in itself about a specific system's environmental profile.

Recycling is the other track. When materials such as lithium, nickel and cobalt are recovered rather than newly mined, there is a documented gain. Recycled battery materials on average entail significantly lower greenhouse gas emissions than the corresponding materials from mining, and recycling can reduce the need for new mining considerably towards 2050. Recycling does not, however, replace mining entirely, and the gain depends on batteries actually being collected and treated with suitable processes. That is precisely the kind of requirement the EU Battery Regulation gradually makes binding. At end-of-life, responsible decommissioning also requires a plan that covers risk assessment, an environmental assessment and concrete considerations of recycling and disposal. Circularity is, in other words, something that must be planned and carried out, not a property the hardware has by itself.

Why "green hardware" is a claim that must be documented

Putting the pieces together, a picture emerges that is both positive and conditional. LFP is cobalt-free, more thermally stable and, in many life cycle assessments, performs better than NMC. But the chemistry still has a footprint, the overall environmental profile depends on production, operation and end-of-life, and for stationary systems even the comparison between the chemistries is not clear-cut.

That has a direct consequence for communication. Calling a system "green hardware" is a general environmental claim, and general environmental claims are precisely the type subject to strict documentation requirements. A claim that the hardware is green in practice requires a life cycle assessment that looks at more than climate, and documentation that can be verified. If that is not possible, the honest formulation is different: that LFP has some concrete advantages that can be described, that the system can support better utilisation of renewable energy, and that the full environmental profile requires documentation you should not claim in advance. We go further into the pitfalls of green claims in the article on greenwashing and energy storage, and into lifetime, which is a central part of the calculation, in our guide to a BESS system's real lifetime.

ZynexGroup's approach to system assessment

Our role is bounded, and it should be described that way. We deliver hardware, commercial optimisation of the system's flexibility and access to operational data. We are not ESG advisers or auditors, and we do not prepare sustainability reports for the customer. When it comes to battery chemistry, we prioritise operational safety and robustness in an industrial BESS system, and we speak soberly about what the chemistry and the life cycle involve, rather than placing a green label on top of the hardware.

Concretely, our platform can make generic operational data available, for example energy throughput, cycles, state of charge and uptime. That is operational data that the customer and the customer's own advisers can use in their own documentation, including for a life cycle or environmental assessment if they choose to produce one. The assessment itself, and any external environmental claim, belongs with the customer and their professional adviser, not with us. We offer a real 6-year payback guarantee on BESS systems. It concerns the economics and says nothing about the environmental profile, and the two questions should be kept separate.

Overall perspective

LFP and NMC are two chemistries with different profiles. LFP is cobalt-free, more thermally stable and today dominates stationary storage, but it is less energy-dense, and it still has an environmental footprint. Fire and safety are not a side track to sustainability, but part of it, and the life cycle from production through operation to recycling determines the overall profile. Second life and recycling hold real potential, but must be described with caveats and planned for.

For a company, the useful conclusion is sober. Hardware can have concrete, describable advantages, but "green hardware" is a claim that must be documented across the full life cycle, not a property you can read off from the chemistry. The honest position is to highlight what can be substantiated, and to be clear about what cannot.

Get an assessment of your facility's potential

If you want clarity on what a battery can realistically contribute at your site, we are happy to have a data-based conversation. We start from your own data: grid connection, consumption profile and history. On that basis we make an initial assessment of whether there is a match, and we are clear that a proper life cycle or environmental assessment is a task for your own professional adviser, not for us. You are welcome to contact us.