Metal-air batteries: Correlation
Prices it moves with, and why
Metal-air batteries draw oxygen from the air, so they carry only the metal. Zinc-air cells for hearing aids are mature, while aluminium-air and iron-air for grid storage are early. Cost follows the metal and cell design.
Proxy US PPI: primary batteries index · monthly, Jan 2006 to Sep 2026There is no free public price for metal-air batteries itself, so this tab uses the closest public series as a stand-in. Read the numbers as an indication, not as the price of this exact item.
What its price moves with
Selected linkMetal-air batteries and Zinc
Monthly changes -0.04 little or none correlation 12-month changes -0.25 weak correlation Last 5 years -0.35 monthly changes Lead or lag −1 mo Metal-air batteries tends to lead by 1 month (r 0.07) Price function, Jan 2006 to Sep 2026 Metal-air batteries ≈ 41.3 × (Zinc)0.14 R² 0.12 On this fit, a 10% higher zinc price goes with a 1.4% higher metal-air batteries price over the long run. Units: index and $/mt. The fit is loose, so treat the function as a rough guide.Chart: Metal-air batteries and Zinc prices rebased to 100 at Jan 2006, log scale
Both prices rebased to 100 at Jan 2006, on a log scale so equal percentage moves look the same size.Chart: Metal-air batteries price against Zinc price, monthly, log scales, with fitted line
Each dot is one month; paler dots are older (2006), darker dots recent (2026); the ringed dot is the latest month. The dashed line is the fitted price function. Both axes are logarithmic.Zinc-air cells oxidise zinc powder, and zinc is their main material cost. The primary battery proxy covers many chemistries, so it shows no link to zinc, with monthly moves at -0.04 and yearly moves at -0.25.
little or none co-movement month to month · 249 months Show chartsAluminium-air cells offer very high energy but consume their aluminium plates, which must be recycled at smelters. The proxy shows no link to aluminium, with monthly moves at -0.07, since aluminium-air is still a niche.
little or none co-movement month to month · 249 months Show chartsIron-air batteries for multi-day grid storage rust and un-rust iron pellets, aiming at very low cost because iron is cheap. The primary battery proxy cannot reflect this new market, and shows no link, with monthly moves at -0.02.
little or none co-movement month to month · 249 months Show chartsThe potassium hydroxide electrolyte is made in chlor-alkali plants, the same process that makes caustic soda. The alkalies proxy shows a modest link, at 0.22 for monthly moves and 0.52 for yearly moves, partly through shared US chemical inflation.
weak co-movement month to month · 249 months Show chartsFor grid storage, iron-air competes with LFP on cost per stored hour over long durations. The two battery indices correlate at 0.48 for yearly moves, but only at 0.01 for monthly moves.
little or none co-movement month to month · 243 months Show chartsZinc-air hearing aid cells are primary batteries, so the site uses the US primary battery index for metal-air too. The two series are identical, so no separate statistics are shown.
Not enough overlapping price history to measure.How to read these numbers
Correlation of monthly changes (the number in the coloured pill) compares how much each price moved, month by month, since 2006 or the first month both series exist. It runs from −1 to +1: near +1 the two usually rise and fall in the same months, near 0 there is no link, and a negative number means they tend to move in opposite directions. Above 0.7 is strong, 0.4 to 0.7 moderate, 0.2 to 0.4 weak.
12-month changes compare year-on-year moves, which shows whether two prices share the same cycles even when the month-to-month noise differs.
Price function is a straight-line fit of the two prices on logarithmic scales: price ≈ k × (partner price)β. β is how much this price moves, in per cent, for a 1% move in the partner over the whole period, and R² is the share of the variation the fit explains. Two prices that both drift up with inflation can fit well without any real link, so read it together with the monthly correlation.
Lead or lag checks whether the monthly correlation is clearly higher when one price is shifted by 1 to 6 months.
Correlation is not cause. The reasons on each card explain the economic link; the numbers show how strongly it has shown up in prices. Proxy series are US producer price indexes or related prices and can blur the real link.
Data: World Bank Commodity Price Data (Pink Sheet), October 2026; US Bureau of Labor Statistics producer price indexes, IMF primary commodity prices and US EIA prices via FRED, Federal Reserve Bank of St. Louis, retrieved November 2026. Calculations by this site.