Sodium-ion batteries enter grid storage: the 2026 breakthrough and what it means for testing

#From pilot to product

For years, sodium-ion was the chemistry of announcements. In 2026 it became a purchase order. In April CATL signed a three-year agreement with storage integrator HyperStrong for 60 GWh of sodium-ion batteries — the largest sodium-ion order to date and, by Electrek’s estimate, about half of CATL’s total storage battery shipments in 2025. CATL says it has solved mass production across the whole chain and began delivering sodium-ion storage systems this year.

Others are moving too. In the US, Peak Energy plans to supply Jupiter Power with up to 4.75 GWh of sodium-ion storage by 2030, starting with about 720 MWh in 2027. In Korea, the government’s battery roadmap of 22 September 2026 makes sodium-ion a priority for energy storage, with targets of 160 Wh/kg by 2027 and 220 Wh/kg by 2030.

#Why storage, and why now

Weight matters little in a container on the ground. Cold-weather performance, cycle life and independence from lithium prices matter a lot. China’s import dependence for lithium resources is cited at 72 %, and lithium’s share of China’s new-type storage fell from 97.5 % at the end of 2025 to 94 % in the first half of 2026, according to Tsinghua professor Li Jinghong.

Cost is the open question. A 100 MWh project in Renqiu, Hebei, was reported at around 1 yuan/Wh at system level. Industry expects sodium-ion cells to reach about 0.35 yuan/Wh — parity with lithium — around the end of 2028.

#The new national standards

On 28 August 2026 SAMR and SAC published two recommended national standards for sodium-ion batteries in electrical energy storage, both applying from 1 March 2027:

• GB/T 48072-2026 — safety requirements and test methods for cells and battery packs, covering telecom, UPS and emergency power, PV systems, home storage and large-scale storage.
• GB/T 48098-2026 — technical (performance) requirements.

They follow the lithium framework but tighten key tests, according to the China Electronics Standardization Institute: nail penetration goes fully through the cell instead of a shallow puncture, and the drop test uses 1.5 m for cells and 2 m for modules. Performance requirements reported for the technical standard include energy efficiency of at least 92 %, at least 90 % capacity retention after 1 000 cycles and capacity checks at −20 °C, −30 °C and −40 °C. Industry voices expect the standards to become mandatory later; no official decision has been published. Four international standards for sodium-ion batteries are being drafted.

#What system makers should check

• Standards route. For China, plan against GB/T 48072/48098 before March 2027. For export markets, sodium-ion projects still go through system-level safety (UL 9540 / UL 9540A in North America) — the fire tests apply to any chemistry.
• Voltage window. Sodium-ion cells have a lower nominal voltage and a wider operating window than LFP. PCS DC input range, BMS limits and pre-charge design have to be checked for the full window, not copied from the lithium version.
• Cold climate claims. Low-temperature capacity and charge acceptance at −20 °C to −40 °C should be measured at system level, including the PCS, before they go into tenders.
• Grid code. The chemistry changes nothing for grid connection: the PCS still needs the grid-code certificate of each market.

TSINGHU tests storage converters and systems up to 2.5 MW in China — including performance across the battery voltage window, climatic tests and grid-code compliance — so sodium-ion systems can be verified with the same evidence chain as lithium ones.