In Polarium’s Five Layers of Safety framework, cell-level safety is the foundation on which every other protection layer is built. The quality, performance, and safety of each cell directly impact the reliability of the battery module, and in turn, the overall energy storage system.
Polarium does not manufacture cells. Instead, it partners with leading global cell manufacturers, including Samsung, to source high-performance lithium-ion cells in both LFP and NMC chemistries. This allows customers to choose the chemistry best suited to their application, whether that is the high energy density of NMC or the enhanced thermal stability of LFP.
Chemistry Selection for Application Needs
Polarium offers both Lithium Iron Phosphate (LFP) and Nickel Manganese Cobalt (NMC) chemistries. LFP cells are well known for their high thermal stability, long cycle life, and enhanced safety profile, making them ideal for applications where maximum operational life and safety margins are the primary concern. NMC cells provide higher energy density, allowing more capacity to be stored within a compact footprint, which is advantageous for space-constrained installations. This flexibility allows customers to select the most appropriate chemistry for their specific application, whether it be long-term standby power or high-density energy storage in metropolitan sites.
Rigorous Cell Testing and Qualification
Before a cell type is approved for integration into a Polarium product, it undergoes an extensive validation and verification program conducted by Polarium’s in-house R&D team. This process screens for electrical, thermal, mechanical, and safety performance, ensuring the chosen cell meets strict quality and durability standards.
The screening program includes:
- Electrical Testing: Over-voltage, over-charge current, over-discharge current, and short-circuit performance checks.
- Thermal and Environmental Testing: Operation at temperature extremes, humidity, altitude simulation, and leakage current monitoring.
- Mechanical and Abuse Testing: Vibration, drop, crush, and impact testing to ensure the cell can withstand mechanical stress during shipping, installation, and service life.
- Safety Function Verification: Evaluation of circuit breaker function, prevention of abnormal temperature rise, and assessment of cell behaviour under thermal runaway conditions.
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Performance and Load Testing: Capacity verification, polarity checks, and continuous load performance evaluation to ensure stable operation across the full operating range.
Only cells that pass every stage of testing are approved for use in Polarium’s battery modules.
Photo credit: Polarium's State of the Art Technology Centre
Intrinsic Safety Design
Every cell features internal safety mechanisms designed to contain and mitigate failures should they occur. These include pressure relief vents, shutdown separators, and current interrupt devices. Combined, these features prevent thermal runaway from propagating beyond the cell level. The result is a robust first layer of protection within Polarium’s five-layer safety architecture.
Transparency and Control from the Start
Cell-level safety does not exist in isolation. The integration of high-quality, well-tested cells forms the foundation for the higher layers of safety that Polarium provides. Once cells are assembled into a module, the Battery Management System (BMS) continuously monitors their voltage, temperature, and state of charge. This level of visibility ensures that any potential deviation from safe operating parameters is detected early and addressed before it becomes a risk.
If you would like to learn more about how Polarium lithium-ion batteries, supplied by Powerbox, can strengthen both safety and reliability in your back up telecommunications or industrial applications, contact our team to discuss your site requirements and system design needs.
Next in the Series
In Part 2: Module-Level Safety, we will examine how Polarium’s patented welding process, flexible printed power board (PPCB) tracks, and structural innovations reduce mechanical failure risks, enhance vibration resistance, and maintain safety under challenging environmental conditions.
