PVDF Binder Grades Compared: HSV900 vs 5130 vs 761 for Electrodes

This PVDF binder grade comparison comes down to three jobs. Choose Solef 5130 when adhesion and electrolyte resistance dominate: high-nickel NMC, thick coatings, long cycle-life targets. Choose Kynar HSV 900 when you want a binder Arkema explicitly positions for LFP cathodes, with a published transition-metal purity limit. Choose Kynar 761A only when you need a cheap, lower-viscosity PVDF for solution work and can accept that Arkema does not sell it as a battery binder.

The part most comparisons skip: you cannot swap these three at the same weight percent and call it a fair test. Below is what actually changes in the slurry, what one published head-to-head measured, and how to run the swap so your cell data still means something.

Quick answer: which PVDF binder grade fits which job

Each grade is built for a different point in the process window. The table below is the short version; every figure is from the current manufacturer datasheet unless flagged.

	Solef 5130 (Syensqo)	Kynar HSV 900 (Arkema)	Kynar 761A (Arkema)
Marketed as	Solef 5000-series binder for xEV traction batteries	LFP cathode and edge-coating binder	General-purpose Kynar 700-series homopolymer powder
Melting point	~162 °C	165 °C	~165–170 °C for 700-series homopolymer [VERIFY]
Published viscosity figure	Intrinsic viscosity 0.27–0.37 L/g	Melt viscosity 50 kPoise (230 °C, 100 s⁻¹); solution viscosity 510 cPo (5%, 16.8 s⁻¹)	Not published in a battery-binder context [VERIFY]
Metals limit on TDS	Not stated on public TDS [VERIFY]	Cr, Fe, Co, Ni, Cu, Zn each <5 ppm	Not stated in a battery context [VERIFY]
Powder D50	Not stated on public TDS [VERIFY]	10 µm	Not stated [VERIFY]
Density	1.75–1.80 g/cm³	1.78 g/cm³	~1.78 g/cm³ [VERIFY]
Best fit	High-Ni NMC/NCA, thick or high-loading coatings, long-cycle programmes	LFP cathodes, edge coating, general lab cathode work	Cost-driven screening, membranes, non-critical coatings
Main trade-off	Highest slurry viscosity, which caps your solids loading	Mid-range peel in at least one published LFP comparison	No battery positioning and no purity claim you can point to

 

What actually separates 5130, HSV 900 and 761A

All three are polyvinylidene fluoride (PVDF) homopolymer powders that dissolve in NMP. The differences are molecular weight, crystallinity, particle size and, critically, how each supplier positions and specifies the grade.

Solef 5130: the adhesion-first grade

Solef 5130 (full grade name Solef 5130/1001) sits in Syensqo's Solef 5000 series, the family designed specifically as an electrode binder for electric-vehicle traction cells. Published figures include an intrinsic viscosity of 0.27–0.37 L/g, a melting point near 162 °C, a glass transition around −40 °C, and thermal stability above 375 °C by TGA.

Syensqo's durability argument is a soak test rather than a peel number: cathodes are immersed in EC/DMC 1:1 at 85 °C for five days, then weighed to see how much active material stayed on the collector. That matters if you are chasing 1,000+ cycles or elevated-temperature abuse, because binder swelling is what loosens the carbon network long before the active material fails.

One thing the public documents do not settle: whether 5130's adhesion advantage comes purely from ultra-high molecular weight or from chain modification. Solvay's 2016 launch of the sister grade 5140 explicitly described polar functional groups distributed along the fluoropolymer chain. The public material on 5130 does not spell that out. [VERIFY with your Syensqo contact if the distinction matters to your formulation IP.]

Kynar HSV 900: the LFP workhorse with a purity spec

Arkema's current technical data sheet describes HSV 900 as a high molecular mass vinylidene fluoride homopolymer used principally as an LFP cathode and edge-coating binder. Typical values: melt viscosity 50 kPoise at 230 °C and 100 s⁻¹ (ASTM D3835), solution viscosity 510 cPo at 5% PVDF and 16.8 s⁻¹ (GB/T 10247), melting temperature 165 °C, D50 of 10 µm, density 1.78 g/cm³, supplied in 20 kg boxes.

The line worth circling is the metals limit: chromium, iron, cobalt, nickel, copper and zinc each below 5 ppm. Transition-metal contamination is what produces soft shorts and elevated self-discharge, and it is the failure mode that shows up months later in a cycle-life dataset. A binder with no stated limit leaves that variable open.

A published GPC study of HSV 900 also found a bimodal molecular-weight distribution rather than a single population, which is part of why a resin this viscous still dissolves manageably. Treat the absolute molecular weights in that paper cautiously; the ultra-high-mass peak looks like it includes aggregates rather than true chains.

Kynar 761A: a solution-grade resin, not a battery binder

Kynar 761A is a Kynar 700-series fluorinated homopolymer supplied as powder. Arkema's product page sells it on chemical resistance, UV resistance, barrier properties and purity, which is the language of pipe, architectural coatings and membranes. It does not appear in Arkema's battery electrode binder line, which is built around the HSV series (HSV 900, HSV 1800, HSV 1810).

That does not make it useless in a lab. It dissolves in NMP, it coats, and it costs less. What you give up is a battery-specific purity claim, a battery-specific rheology spec, and a supplier who will troubleshoot a gelled cathode slurry with you. Its lower solution viscosity per unit mass also means you need more of it to hit the same slurry rheology, which eats directly into your active-material fraction.

The number that decides your grade: solution viscosity at your solids loading

The single most common mistake in a PVDF binder grade comparison is treating three different viscosity measurements as if they were the same number. They are not.

• Melt viscosity (kPoise) is measured on molten polymer at 230 °C with no solvent present. 1 kPoise = 100 Pa·s.
• Solution viscosity (cPo, equal to mPa·s) is measured on a solution at a stated concentration and shear rate. HSV 900's 510 cPo figure is at 5% and 16.8 s⁻¹.
• Intrinsic viscosity (L/g or dL/g) is an extrapolation to infinite dilution. It is a molecular-weight proxy, not a process number.

None of the three tells you what your slurry will do at 8 wt% binder solution and 65 wt% solids in your mixer. Comparing 50 kPoise against 0.27 L/g is comparing an engine temperature to a fuel-tank volume.

Do this instead. One afternoon of benchwork replaces a week of datasheet argument:

1. Make an 8 wt% solution of each candidate in dry NMP. Check the NMP water content first; anything much above roughly 200 ppm will fight you.
2. Stir 12 to 24 hours at 40–50 °C until the solution is clear with no fisheyes. Add powder slowly into a vortex rather than dumping it in.
3. Measure all three on the same viscometer, at 25 °C, at one fixed shear rate or spindle speed that you write down.
4. Record the ratios between them. That ratio, not the datasheet, is what you compensate for with NMP when you change grades.

Expect 5130 to sit well above HSV 900, and HSV 900 well above 761A, at equal concentration. If your planetary mixer or coater has a practical viscosity ceiling, that ordering can decide the grade before adhesion ever enters the conversation.

What a published head-to-head between HSV 900 and Solef 5130 measured

A 2023 study from IIT Kanpur (Nishanth et al., Oxford Open Materials Science, DOI 10.1093/oxfmat/itad019) ran Kynar HSV 900 and Solef 5130 through an identical LFP cathode process and reported the full chain from powder characterisation to 500 cycles. It is the most complete public head-to-head on these two grades.

Measurement	Kynar HSV 900	Solef 5130
Crystallinity (DSC)	14%	32%
α / β phase split (FTIR)	50.7% / 49.3%	72.1% / 27.9%
Powder particle size (FESEM)	311 nm	152 nm
Solution viscosity (2.5 w/v in NMP)	32.8 Pa·s	86.3 Pa·s
180° peel, LFP coating on Al	1.30 N/cm	11.42 N/cm
Electrolyte uptake, 48 h soak	18.9%	11.5%
Charge-transfer resistance	118.2 Ω	87.2 Ω
First-cycle capacity at 1C	134 mAh/g	146 mAh/g
Capacity retention, 500 cycles at 1C	64%	82%
Mean crack width after 500 cycles	13.4 ± 5.5 µm	6.2 ± 3.3 µm

 

Their process, for context: LFP : conductive carbon : PVDF at 80 : 10 : 10 wt%, mixed in a Thinky ARE-310 at 2,200 rpm for 10 minutes, blade-coated on aluminium, vacuum-dried 12 hours at 120 °C, calendered at 80 °C to roughly 40% porosity. Final coating 32 µm at 2.6 mg/cm², built into 2032 coin cells with 1 M LiPF6 in EC:DEC and a Celgard 2325 separator.

Read it with the caveats. The binder fraction is 10 wt%, roughly three times a production LFP electrode, and peel strength is extremely sensitive to binder fraction. The gap will compress at 2–3 wt%. Both slurries were also run at an identical recipe rather than re-optimised per binder, and the authors themselves attribute much of 5130's advantage to its higher slurry viscosity generating more shear and therefore better carbon dispersion. That is a process effect you could partly recover by re-tuning the HSV 900 slurry.

So the defensible conclusion is narrower than "5130 wins," and more useful: binder grade changes electrode microstructure, and microstructure changes cycle life. Arkema, meanwhile, positions HSV 900 specifically for LFP cathodes. One study is a signal, not a verdict.

Walkthrough 1: swapping binder grades without invalidating your cell data

Most grade comparisons run in labs are confounded from step one, because the team holds binder weight percent constant and lets slurry viscosity float. That bundles binder chemistry together with dispersion quality, coating thickness and porosity, and you can no longer say which one moved the result. Run it this way instead.

1. Decide what you are holding constant. Binder wt% answers "which binder is better in my existing recipe." Constant slurry viscosity answers "which polymer is the better binder." Pick one and say so in the report.
2. Prepare single-grade binder solutions at one common concentration, typically 6–8 wt% in NMP. Never blend grades in a comparison arm.
3. Measure and record each solution's viscosity on the same instrument, temperature and shear rate. This is your baseline and your audit trail.
4. Build each slurry to a viscosity target rather than a fixed solids number. Adjust with NMP, not with binder. For a lab blade coater, somewhere in the 3,000–6,000 mPa·s range at moderate shear is a reasonable starting window; your coater will have its own. [VERIFY against your own equipment]
5. Coat every arm at the same wet gap and the same line speed, then confirm dry areal loading is within about ±3% across arms. If it is not, fix it before you go further.
6. Calendar every arm to the same porosity, not the same thickness. Equal thickness at unequal porosity is a different electrode.
7. Only now run peel, electrolyte soak and cells, and build at least three cells per arm.

What goes wrong: skip steps 5 and 6 and you will confidently attribute a 12% loading difference to binder chemistry. It happens constantly, and it survives peer review more often than it should.

Walkthrough 2: a 20 g NMC811 lab batch with Solef 5130

Here is a concrete starting recipe for a coin-cell-scale high-nickel cathode, at a 96 : 2 : 2 ratio of active material, carbon black and binder.

• Total solids target: 20.0 g, giving 19.2 g NMC811, 0.4 g C65 conductive carbon and 0.4 g Solef 5130.
• Binder solution: 5.0 g of an 8 wt% 5130-in-NMP solution supplies the 0.4 g of binder plus 4.6 g of NMP.
• Dry-blend the carbon black with a portion of the NMC811 first. Carbon black is the hardest component to disperse, and it will not recover later.
• Add the binder solution, mix, then thin to your target solids with additional NMP. For NMC on a lab planetary mixer, 65–72 wt% solids is a common working range. [VERIFY for your mixer and material lot]
• Coat, dry at 80–120 °C, then vacuum-dry the electrode 12 hours at 120 °C before it enters the glovebox.

The failure to watch for: overnight gelation. Residual surface lithium species on high-nickel NMC (Li₂CO₃ and LiOH) raise slurry pH, which can dehydrofluorinate PVDF and cross-link the slurry into jelly. You will find it the next morning, not during mixing. Solvay built the 5000-series messaging partly around resisting exactly this in high-Ni NMC and NCA. Practical countermeasures: use fresh, low-residual-lithium active material, keep NMP dry, mix and coat the same day, and if you must hold a batch, hold it cold and under nitrogen.

What it costs, and the mistakes that cost more

Battery-grade PVDF binder spot pricing was estimated at roughly USD 20–25/kg entering 2026 in IndexBox's market forecast. [Market-research estimate, not a transacted price. VERIFY against your own quotes.] Lab quantities in 50–500 g bottles run far higher on a per-kilogram basis, which is normal and not a reason to avoid the better grade.

Run the arithmetic before optimising for resin price. At 2 wt% binder loading and USD 25/kg, binder contributes about USD 0.50 per kilogram of finished cathode. A 30% price gap between grades is therefore roughly USD 0.15 per kilogram of cathode, against an active material that dominates the cost line by an order of magnitude.

Binder loading moves the number far more than binder price does. LFP formulations conventionally carry more PVDF than nickel-rich ternary ones, on the order of 3–3.5% versus 1.5–2%. [VERIFY against your own formulations; this is an industry rule of thumb, not a specification.]

And the genuinely expensive failures are never the resin:

• A 5 kg pilot batch of high-Ni slurry gelled overnight and scrapped.
• A coating run was rejected for mud-cracking because solids were pushed too high on a grade that could not carry it.
• Cells pulled at 300 cycles because edge delamination started early.

Any one of those costs more than a year of binder premium.

Where this comparison stops applying

This comparison assumes an NMP-based cathode slurry. Outside that, the grade question changes or disappears.

• Dry electrode processing. Fibrillated PTFE, not PVDF, does the binding. None of these grades applies.
• Aqueous binder systems. CMC/SBR, PAA and LA133 are water-processed and cheaper. One comparative study on transition-metal-oxide anodes found SBR+CMC and LA133 outperformed HSV 900, PVDF 301F and Solef 5130 on cycling and rate.
• Graphite anodes. SBR/CMC dominates on cost and solvent grounds. PVDF on an anode is usually a research choice, not a manufacturing one.
• Silicon-bearing anodes. PVDF does not accommodate the volume change. You want a covalently bonding or self-healing system instead.
• Separator coatings. PVDF-HFP copolymers are used there for controlled swelling and wettability, not these homopolymers.
• Regulatory horizon. PFAS restriction proposals in the EU are still unresolved and touch fluoropolymers. If that is material to your programme, track it directly rather than relying on any article. [VERIFY current status]

Five mistakes to avoid when comparing PVDF binder grades

Every one of these has cost someone a month of data.

1. Comparing melt viscosity to solution viscosity. Different measurement, different physics, no valid ratio between them.
2. Swapping grades at constant weight percent and calling the result a binder comparison. It is a rheology comparison wearing a costume.
3. Ignoring NMP water content. Wet NMP slows dissolution, encourages gelation, and leaves residual moisture that shows up as gassing in the cell.
4. Leaving PVDF powder open on the bench. It picks up moisture. Reseal it, and dry it if it has been open. [VERIFY drying conditions against the supplier TDS before heating any fluoropolymer.]
5. Assuming an unspecified grade meets an unstated purity level. If the datasheet does not carry a transition-metal limit, you do not have one.

Frequently asked questions

Can I substitute Kynar 761A for HSV 900 at the same weight percent?

No, not without re-tuning. 761A has a lower solution viscosity, so an equal weight percent gives you a thinner slurry, weaker shear during mixing and poorer carbon dispersion. Match slurry viscosity instead, then verify peel strength and areal loading before you compare any cell data.

Why did my PVDF cathode slurry turn into jelly overnight?

Usually residual surface lithium on high-nickel active material. Li₂CO₃ and LiOH raise slurry pH, which can dehydrofluorinate PVDF and cross-link the slurry. Use fresh low-residual-lithium material, keep NMP dry, and coat the same day you mix. Binder grades marketed for high-Ni cathodes are formulated to resist this.

Does Solef 5130 always give better adhesion than Kynar HSV 900?

No. One published LFP study measured 11.42 N/cm for 5130 versus 1.30 N/cm for HSV 900, but at an unusually high 10 wt% binder and without re-optimising either slurry. Arkema positions HSV 900 specifically for LFP cathodes. Test both in your own formulation.

How much PVDF binder should a cathode contain?

Industry practice is roughly 3–3.5 wt% for LFP and 1.5–2 wt% for nickel-rich ternary cathodes, because LFP's higher surface area needs more binder to hold the network together. Lab formulations often run higher, sometimes 5–10 wt%, which exaggerates binder differences. Verify against your own electrodes.

How do I compare viscosity numbers from different PVDF datasheets?

You mostly cannot, because suppliers publish different measurements. Melt viscosity in kPoise, solution viscosity in cPo at a stated concentration, and intrinsic viscosity in L/g are three separate things. Measure candidates grade themselves at one common concentration, temperature and shear rate.

Which PVDF grade is best for a high-nickel NMC811 cathode?

Solef 5130 or an equivalent binder-line grade is the safer starting point, because high-Ni cathodes are prone to slurry gelation and to binder swelling over long cycling. Confirm your mixer can handle the higher slurry viscosity, and screen a second grade in parallel before committing.

Conclusion

Solef 5130 buys adhesion and low electrolyte uptake at the cost of the highest slurry viscosity. Kynar HSV 900 buys a battery-specific purity spec and a well-documented LFP position at a more workable viscosity. Kynar 761A buys cost, and gives up the specification and support that make a cathode reproducible.