The global market for battery separators used in electric vehicles returned to steep growth in 2026. Yet the benefits have been distributed anything but evenly. Chinese manufacturers have tightened their stranglehold on the industry, while SK IE Technology (SKIET), South Korea's leading separator maker, has been left nursing a contraction.

A 7,489 million-square-metre market—with lopsided rewards

According to SNE Research, global separator shipments for EV batteries (covering full-electric, plug-in hybrid, and conventional hybrid vehicles) reached approximately 7,489 million square metres in the first five months of 2026, a rise of 20.7% year on year. Markets outside China performed even more strongly, with shipments of around 2,605 million square metres representing growth of 38.7%—well above the global average.

Separators are a critical component inside lithium-ion batteries, physically dividing the positive and negative electrodes to prevent short circuits whilst allowing lithium ions to pass through. They are directly linked to battery safety, power output, and longevity, and structural demand continues to grow in step with the expansion of the EV market, rising battery capacity per vehicle, and the wider adoption of high-energy-density cells.

Two distinct forces are driving this growth. Within China, a surge in large-scale production of LFP (lithium iron phosphate) battery cells is the primary catalyst. Outside China, a combination of recovering EV sales in Europe and emerging markets, new model launches by major original equipment manufacturers (OEMs), and larger battery packs per vehicle has done the work. That said, production-schedule adjustments by North American and some European OEMs remain a constraint on near-term growth for non-Chinese separator suppliers.

China holds 89.7%; South Korea shrinks to 3.7%

The more troubling story lies in the structure of the market's growth. By nationality of manufacturer, Chinese firms accounted for 89.7% of the global separator market in the first quarter of 2026—up 3.1 percentage points from 86.6% in the same period of 2025, a remarkable consolidation of dominance in just one year.

South Korean manufacturers, by contrast, saw their share fall from 5.1% to 3.7% over the same period, while Japanese firms slipped from 8.3% to 6.6%. The message is unambiguous: as Chinese producers leverage massive capacity expansions and formidable cost advantages to entrench their supremacy in commodity separators, non-Chinese rivals are ceding ground.

Company-level growth figures make the picture even starker. SEMCORP, the market leader, shipped approximately 2,205 million square metres, up 15% year on year. Senior (+19%) and Sinoma (+15%) maintained solid trajectories. Meanwhile, second-tier Chinese players—Gellec (+72%), Lanketu (+75%), and Putailai (+48%)—are expanding at explosive rates.

SKIET: the only non-Chinese supplier in reverse

Against this backdrop, SKIET's performance stood out for all the wrong reasons. In the first five months of 2026, its separator shipments fell 13% year on year—making it virtually the only major supplier to record a decline, and a singular outlier among non-Chinese manufacturers.

Weakening demand is the proximate cause. Adjustments to EV production schedules by North American and European OEMs hit SKIET's order book directly, given the company's deep integration into those supply chains. SKIET supplies European customers through its manufacturing base in Poland, and domestically it counts LG Energy Solution and Samsung SDI among its key clients. Those Korean battery makers, however, are themselves exposed to the same demand slowdown in North America and Europe.

Two pillars of survival: premiumisation and localisation

Industry analysts argue that the structural challenge facing SKIET runs considerably deeper than a short-term demand trough. There is a broad consensus that Chinese manufacturers' cost competitiveness has already reached a level at which non-Chinese rivals cannot survive in commodity separators through head-on competition.

Three strategic directions are emerging as the most credible responses. The first is a move up the value chain. Products such as ceramic-coated separators, high-heat-resistant separators, and ultra-thin variants carry higher technical barriers to entry and command premium pricing. As safety requirements for high-energy-density and fast-charging batteries intensify, demand for such products is structurally bound to grow.

The second is diversification into the energy storage system (ESS) market. Competition in separators is no longer confined to EV applications. The convergence of renewable energy expansion and surging electricity demand from data centres is driving rapid growth in ESS battery demand, creating a new engine of separator consumption. ESS could provide SKIET with a more stable volume base that reduces its dependence on the volatile EV cycle.

The third is building local production capacity and securing supply-chain resilience. As governments—most notably through America's Inflation Reduction Act—continue to press for domestic supply chains, establishing a North American manufacturing footprint emerges as a decisive variable in SKIET's long-term competitiveness. It also represents an opportunity to capture stable demand in markets where Chinese suppliers are structurally excluded on regulatory grounds.

De-risking from China: the wildcard in a market reshaping

Paradoxically, China's overwhelming dominance of separator supply is increasingly viewed as a systemic risk factor within global EV supply chains. Should the technology rivalry between Washington and Beijing and the broader push to reduce Chinese supply-chain dependencies persist, a structural opening could emerge for non-Chinese separator makers. The more forcefully Western OEMs and battery manufacturers move to reduce their China exposure, the more likely it is that demand will recover for non-Chinese suppliers with proven technology and established local supply chains.

That scenario, however, will take time to materialise. In the interim, SKIET faces considerable costs and restructuring pressure. Diversifying production sites and developing premium products demands heavy capital investment, and calibrating the pace of that investment when the timing of any demand recovery remains uncertain is a formidable management challenge in itself.

Outlook: short-term headwinds, medium-term crossroads

The structure of the 2026 separator market presents SKIET with simultaneous headwinds in the near term and a consequential strategic choice over the medium term. Posting a 13% decline in a market growing at more than 20% is a stark verdict on the adequacy of its existing strategy.

Whether SKIET can engineer a recovery in its results will depend not simply on a rebound in shipment volumes, but on how swiftly it can execute on four fronts: diversifying its customer base, building credible ESS capabilities, establishing a North American supply-chain presence, and expanding its premium product portfolio. The global separator market's growth trajectory is not in doubt. What remains to be seen is whether SKIET will be among the beneficiaries—or merely a bystander. Its capacity for strategic execution is being tested now.