If the past month has been a horror story for Samsung Electronics, the past 48 hours have been no less nightmarish for TDK — the Japanese company that produces lithium ion batteries for smartphone manufacturers around the world and whose biggest customer is Apple.

TDK had supplied the batteries for replacement Note 7 models, which were proving to be as fire prone as the original recalled smartphones. But while Tuesday’s total halt in production and decision to scrap the Note 7 may strip TDK of a massive potential rise in demand, it also appears to remove the potential taint that batteries were the central culprit in the crisis.

When Samsung’s first recall was issued in early September, the situation appeared to be a huge boost for TDK and its battery-producing subsidiary, Amperex Technology (ATL) — a company founded in Hong Kong in 1999, bought by TDK in 2005 and, according to those familiar with the company, thoroughly “Japanised” in its manufacturing processes by 2010.

The overwhelming majority of Samsung phones that had burst so alarmingly into flames had used batteries produced by Samsung SDI, an affiliate company, and the problems did not initially appear to affect those made by ATL, which were used in around 35 per cent of the Galaxy Note 7 units, according to analysts.

As a temporary solution to its crisis, Samsung asked ATL to supply batteries for the replacement devices and TDK shares jumped accordingly, as investors relished the boost to sales.

On Monday, however, incidents of explosions surfaced with replacement phones that had used ATL components, suggesting that it too might be churning out batteries that put airline passengers at risk. But with its abrupt decision to cancel all production of the Note 7, say analysts, Samsung appeared to acknowledge that the problem lay outside the batteries themselves.

ATL and TDK declined to comment on Tuesday.

Amperex has displayed astonishingly steep growth since 2005, thanks to its technology choices: the company focused its R&D spending on polymer battery technology and fast-charging capabilities, while rivals like Sony were concentrating their efforts on battery density. End users appeared to prefer Amperex’s attributes and the smartphone makers either had to buy its products or find another supplier that could catch up quickly.

The company is now the world’s fourth-largest supplier of lithium ion batteries, with a 10 per cent market share — versus 8 per cent for Sony — in 2015, according to research firm Techno Systems Research. Analysts say around 65 per cent of ATL’s revenues come from smartphones — half of that coming from Apple, which uses the Japanese company’s batteries in an estimated 80 per cent of units of its new iPhone 7 model.

In three years, ATL’s annual revenue, on an unconsolidated basis, has jumped 47 per cent to ¥165bn ($1.6bn) for the 2015-2016 fiscal year, although its net profit has shrunk to ¥1.5bn from ¥4.4bn during that period. In addition to supplying Apple, the company also makes batteries for electric vehicles, drones and energy storage systems.

Additional reporting by Bryan Harris