NFPP vs NFS: Who Will Dominate the Polyanion Sodium-Ion Battery Race?

The sodium-ion battery sector is undergoing a profound shift in its technology roadmap.

In the early stages of industry development, layered oxide sodium-ion battery technology, leveraging its theoretical high energy density and targeting "lithium battery replacement", became the mainstream direction heavily pursued across the sodium-ion battery industry chain.

However, since 2025, market sentiment has clearly turned. The polyanion sodium-ion battery technology route, relying on outstanding advantages such as structural stability and long cycle life, has helped sodium-ion batteries carve out a market position independent of lithium batteries in long-life energy storage demand, thereby achieving a strong overtaking of layered oxide sodium-ion technology. Its share of newly installed sodium-ion battery capacity has exceeded 70%, making it the absolute market leader.

At the same time, within the polyanion system, multiple sub-technology routes are clustered, including NFPP (sodium iron phosphate composite, sodium iron pyrophosphate phosphate), NFS (sodium iron sulphate), and NVP (sodium vanadium phosphate).

Notably, NFPP and NFS have achieved faster commercialisation and are leading the development of the polyanion sector, each following a distinct development trajectory.

The two are not successive versions of technological iteration, but rather two independent solutions, with significant differences in intrinsic material properties, product positioning, and suitable application scenarios.

On the market side, material and battery cell enterprises such as Zoolnasm, Inna New Energy, Chilwee, and Zoolnasm, as well as OEMs including Yadea, Tailing, Xinri, and Hithium, have carried out relevant deployment in two-wheeler and energy storage sectors. This directly reflects an industry reality: top-tier players no longer adopt a "technology bet" mindset, but instead select technology routes based on scenario demand, allowing the two sodium-ion battery cathode material routes of the same origin to each take root in the growth markets where they are better suited.

Same origin, different paths: each technology has its strengths and weaknesses, with scenarios determining the division of labour

NFPP and NFS, both belonging to the polyanion system, feature stable framework structures and outstanding safety, effectively avoiding the structural instability shortcomings of Prussian blue and layered oxide materials. However, the two differ significantly in process maturity, voltage, moisture sensitivity, cycling, and cost, which has led to divergent commercialisation paths.

According to available data, NFPP's core competitiveness lies in its strong structural fault tolerance, slow cycling degradation, relatively mature production processes, and lower barriers to industrialisation. Yet its shortcomings are equally evident: working voltage and energy density are not advantageous, making it difficult to meet the high-power demands of passenger vehicles.

As a result, NFPP technology is currently targeted mainly at utility-scale energy storage scenarios with stringent safety and service life requirements. Combined with its higher process maturity, it has also become the mainstream technology route for sodium-ion batteries used in two-wheelers.

On the materials side, Zoolnasm and Inna New Energy are steadily advancing the large-scale deployment of NFPP. Zoolnasm was the first to complete a 10kt-scale NFPP production line, steadily supplying battery cell enterprises in energy storage and other scenarios. Inna New Energy's 5,000 mt/year NFPP material production line is running at full capacity, with a supporting 10kt-scale base ready to ramp up, continuously releasing capacity to support energy storage demand.

The maturity of materials has also laid the foundation for product iteration at the battery cell level.

Recently, Hithium launched an NFPP-based 785Ah ultra-large-capacity sodium-ion battery cell. According to available data, relying on the material's three-dimensional stable framework, this product offers 20,000 cycles of intrinsic cycle life and a designed service life of 30 years, matching 2-8 hour electricity ESS dispatch scenarios. This is also expected to further amplify the scenario value of NFPP technology's long cycle life.

Chilwee's NFPP sodium-ion batteries have already achieved mass production and large-scale sales, with related products supplied to OEMs such as Yadea, Tailing, and Xinri, which is likely to continue driving greater application of upstream materials.

Unlike NFPP's long cycle life characteristics, NFS technology's greatest advantages are high voltage, high C-rate, and significant cost reduction potential, making it naturally suited to market demand in light-duty power and power-type energy storage scenarios.

At the same time, NFS materials do not contain phosphorus. Against the backdrop of rising phosphorus source prices this year, it offers greater room for material cost reduction.

Zoolnasm is one of the representative enterprises on the NFS route. Its subsidiary Meishan Lina has completed a 10kt-scale NFS material production line and has also planned 30,000 mt of cathode material and 5GWh of sodium-ion battery PACK capacity, thereby connecting the entire chain from material synthesis to system integration.

On the application side, in August this year, Zoolnasm reached a cooperation agreement with Anqing Chaoren under Chilwee Group. The two parties will leverage NFS technology to carry out in-depth collaboration in the two-wheeler, three-wheeler, and low-speed vehicle markets, accelerating the large-scale penetration of sodium-ion batteries in the light-duty power sector.

This cooperation also shows that Chilwee is not solely betting on the NFPP route, but is simultaneously maintaining an NFS technology presence, potentially covering the light-duty power market with different performance requirements.

In addition, Zoolnasm has also reached a cooperation with Sichuan Puli Technology. The two parties will collaborate on power-type scenarios such as backup power for communication base stations, broadening the application boundaries of NFS.

Behind these corporate moves lies the selection logic being established across the industry: there is no "universal sodium-ion battery" that excels in all scenarios, only better solutions matched to end-use demand. NFPP, with its long cycle life and process maturity, is taking root in long duration energy storage (LDES) and light-duty power sectors. NFS, with its high voltage and high power characteristics, is capturing the power-type market and is expected to enhance the application potential of sodium-ion batteries in high-load, high-speed scenarios for e-bikes and e-motorcycles, allowing each to play to its strengths.

Both routes face bottlenecks in industrialisation

While scenario advantages have been established, both routes still face their own technical and manufacturing hurdles that need to be overcome for industrialisation.

For the NFPP route, the greatest limitations are concentrated in energy density and process difficulty. The limited room for improving material compaction density may impose a natural ceiling on battery cell energy density, making it difficult to enter passenger vehicle power scenarios.

If doping modification is used to optimise material capacity and break through scenario boundaries, long-term process development efforts will still be required.

The core challenge for the NFS route, meanwhile, lies in material stability and mass production control. NFS materials are highly hygroscopic, and trace moisture can easily trigger side reactions, affecting battery cell cycling performance and batch consistency. As a result, stringent requirements are imposed on production workshop dew point and humidity standards. At the same time, the high-voltage platform places higher demands on electrolyte and interface film quality, making mass production yield control more difficult.

Additionally, constrained by intrinsic chemical properties, conventional NFS battery cells lack sufficient long-cycle capability, which also requires collaborative improvement across the industry chain.

According to available data, Zoolnasm has, through process optimisation and architecture upgrades, partially compensated for NFS's inherent shortcomings and successfully achieved large-scale delivery.

It is expected that in the short to medium term, the polyanion sector will not see a situation where "one route eliminates the other", but will instead move towards a pattern of scenario-based division of labour and coexistence.

The division of labour between NFPP and NFS means the sector has entered a new stage of demand-based adaptation. The core of competition in the sector is no longer a comparison of single parameters, but rather a focus on scenario implementation and value realisation.

In the long term, enhancing the full-chain engineering capability of technology routes is particularly important, including precursor consistency, production line energy consumption, batch stability, and the ability to co-develop with downstream battery cell manufacturers. These two routes are likely to leverage their respective strengths to jointly underpin the industrialisation of the polyanion sector.