Over the past few years, there have been several different types of battery cell chemistry used in home energy storage systems, some much safer than others.
Most manufacturers are now converging on using the same chemistry. This chemistry is known as LiFePO4 or Lithium Iron Phosphate / Lithium Ferror Phosphate.
Which type do Vultra use?
The battery cell chemistry that we use is LiFePO4, otherwise known as lithium iron phosphate or lithium ferrophosphate (LFP).
LFP is a type of lithium-ion battery using lithium iron phosphate as the cathode material, and a graphitic carbon electrode with a metallic backing as the anode.
Why is this cell chemistry so good?
This cell chemistry has several key benefits:
- Low cost - A 2020 report published by the Department of Energy in the USA, compared the costs of large scale energy storage systems built with LFP vs NMC (Lithium Nickel Manganese Cobalt Oxide) batteries. It found that the cost per kWh of LFP batteries was about 6% less than NMC, and it projected that the LFP cells would last about 67% longer (more cycles). Over the past 5 years, the average price per kWh of LFP cells has continued to drop, due to it's large scale deployment in EVs and home energy storage systems. Tesla and BYD electric cars both favour LFP batteries.
- High safety - One important advantage of LFP batteries over other lithium-ion chemistries is thermal and chemical stability, which dramatically improves battery safety. LiFePO4 is an intrinsically safer cathode material than other lithium-ion batteries whose negative temperature coefficient of resistance can encourage thermal runaway.
- Low toxicity
- Long cycle life
LFP batteries are finding a number of roles in vehicle use, utility-scale stationary applications, and backup power.