Additional Commentsfrom Battery Association of Japan
Introduction
Battery Association of Japan (BAJ) represents primary and rechargeable battery
industries in Japan. It consists of 15 regular members most of which are battery
manufacturers in Japan and 95 supporting members such as material suppliers,
sales company of overseas battery brands, etc.

BAJ posted the first comments (ref. No.4331 dated May 30.) on info request 8,
in which we presented information such as PFAS usage and key functionalities inbatteries, alternatives feasibility, and economic, social impacts.
This time we aim to reinforce them by answering info request 2 (emission), 3(incineration), and 4 (impacts on the recycling industry).

a. PFAS emissions from batteries by lifecycle
At the battery manufacturing, PFAS is contained in pieces of positive electrodeprocessing, surplus positive electrode mixture and electrolyte, defective batteries
generated in the assembly line, etc., and is collected by recyclers. At the battery
using, PFAS is sealed within the battery container and no outflow occur. At thedisposing, PFAS is contained in waste batteries and goes to recyclers for resource
recovery.
When applying the above to figures of BAJ members’ global production, theamount of PFAS contained in defective batteries, etc. at the manufacturing stage
is approximately 170 tons (10%), and the amount of PFAS contained in wastebatteries at the disposal stage is approximately 1,570 tons (90%).
However, PFAS emissions to the environment are considerably restrained by thecurrent processes of battery recyclers, which we explain about in the following
part of our comments.

b. Effectiveness of incineration in the waste management of PFAS
1) Disposal processes of batteries in Europe
In the past, the EU Battery Directive set targets for the collection rate of usedbatteries, and since they have been raised in stages, recycling of batteries has
become widespread in society. There are many recyclers that specialize inbatteries, and an overview of the recycling process for lithium-ion batteries (LIB)
can be found in the following references.
<Ref.1> R.Sojka, Q.Pan, L.Billmann, “Comparative study of Li-ion battery
recycling processes” ACCUREC Recycling GmbH, Sep. (2020).
https://accurec.de/wp-content/uploads/2021/04/Accurec-Comparativestudy.pdf<Ref.2>A.Rensmo,

E.K.Savvidou,I.T.Cousins,

X.Hu,

S.Schellenberger,

J.P.Benskin, Environmental Science: Processes & Impacts 25 (2023) 1015-1030.
https://pubs.rsc.org/en/content/articlehtml/2023/em/d2em00511e#cit54
According to these, the recycler process converts the battery into black mass(active mass: solid residue) and gas (decomposition product) by heat treatment
at about 600°C, and then melts the black mass at 1000°C or higher(pyrometallurgy) or dissolves the black mass with acid (hydrometallurgy). In
some cases, heat treatment and pyrometallurgy are performed continuously.
2) Effectiveness of incineration on PVDF
In Ref.2, the chemical reaction of PVDF (PFAS used as a binder for positiveelectrode) in the LIB recycling process is shown as follows. PVDF is decomposed
at 400-600°C during heat treatment, and the dehydrogenation reaction duringdecomposition is accelerated by the presence of lithium. As summarized in Fig.
4, PVDF is decomposed to inorganic substances such as HF and LiF, and organic
substances such as CF4 (minimum PFAS), CH3F, CH2CF2, CH3CH2F (short-chaincompounds: non-PFAS), C6H4F2 and C6H3F3 (aromatic compounds: non-PFAS). As
shown on pages 21-22 of Ref.1, these decomposed products are captured by gas
cleaning system in recycling plants and landfilled.
There is no occurrence of highly harmful PFAS, such as those adopted orevaluated by Stockholm (POPs) Convention, in the decomposition products ofheat treatment, and the outflow of fluorine components in final landfill disposal
is managed according to appropriate standards. Therefore, PFAS emissions to theenvironment in the LIB recycling process are currently controlled at a fairly highlevel.
3) Battery systems other than LIB
The above Ref.1 and Ref.2 focus on the recycling of LIB, which are produced inlarge quantities. Other battery systems (nickel metal-hydride batteries andvarious types of primary batteries) as well as the waste and defective batteries
generated during the manufacturing of these systems are treated with almost
the same recycling flow. Therefore, it can be inferred that PFAS emissions due torecycling of other battery systems is also sufficiently suppressed.
4) Complete mineralization by incineration of fluoropolymers
In addition to PVDF, most of the PFAS used in batteries are fluoropolymers suchas PTFE, ETFE, FEP, and PFA. The behavior and emissions during thermal
decomposition of fluoropolymers have been investigated and reported in detail in
the following references.

<Ref.3> J.Bakker, B.Bokkers, M.Broekman, “Per- and polyfluorinated substancesin waste incinerator flue gases” RIVM report (2021) 0143.
https://www.rivm.nl/bibliotheek/rapporten/2021-0143.pdf<Ref.4> K.Aleksandrov, H.J.Gehrmann, M.Hauser, H.Matzing, D.Pigeon, D.Stapf,M.Wexler, Chemosphere 226 (2019) 898-906.
https://www.sciencedirect.com/science/article/pii/S0045653519306435<Ref.5> G.H.Joachim, B.Andrei, A.Krasimir, B.Philipp, T.Philip, S.Michael,A.Bruno, G.Priyanga, K.Deepak, ”Pilot-Scale Fluoropolymer Incineration Study:
Thermal Treatment of a Mixture of Fluoropolymers under Representative
European Municipal Waste Combustor Conditions” : Document attached tocomment from Gujarat Fluorochemicals GmbH to ECHA (ref. No.4587 dated June16.)
https://echa.europa.eu/documents/10162/0d854086-fbba-12ea-094f176dbd7a4dc5
In Ref.3, the order of thermal stability of fluoropolymers is as follows:
PTFE > PFA > FEP > ETFE > PVDF
In Ref.4, the following is shown for the thermal decomposition of PTFE.
・Decomposition of PTFE progresses at 500-650°C
・The estimated half-life of PTFE at 800°C in nitrogen and oxygen atmosphere iswell below 0.1 s, and it completely decomposes within 1 s.
・ High-precision analysis of 31 types of PFAS was performed on the gas
generated by incineration at 870°C for 4.0 s or 1020°C for 2.7 s, simulating theincineration of PTFE in municipal waste, and no generation was observed (thatis, complete mineralization progressed.)
In Ref.5, a mixture of PTFE, PVDF, and PFA is incinerated at 860°C for 2.0 s or1100°C for 2.0 s, and analysis has confirmed that the decomposition productdoes not contain any volatile (1-4 carbon atoms) short-chain PFAS and 51 typesof long-chain PFAS.
Based on above information, it is desirable to increase the temperature during
heat treatment to about 800 to 1100°C for the battery recycling process
mentioned above. As a result, complete mineralization is achieved duringdecomposition of the fluoropolymer, which is presumed to be a safer direction.

The analysis results of heat treatment at 800°C at a recycler in Japan are
attached in Section V. The amount of harmful PFAS produced is sufficiently
suppressed to less than 25 ppb, which is the proposed restriction in EU. The ideal
process would be complete mineralization (decomposition to CO2 and HF) andthe resulting HF to be petrified as CaF2 for recycling.
5) Low-molecular-weight PFAS
In addition to fluoropolymers, low-molecular-weight electrolytes with 1-2 carbon
atoms (both of which contain a CF3-SO2 structure) also exist as PFAS used inbatteries. Although there is no research data for these thermal decompositions,from the binding energy values between CF3-SO2 shown in Table 5 of Ref.3, thesecan be decomposed by heat treatment at about 600°C (or higher) in the recycling
process.

c. Impacts on the recycling industry
As far as we know, with several exceptions of pyrometallurgy, European battery
recyclers are mainly doing heat treatment with temperature of around 600°C.
If they need to raise this temperature to 800-1100°C, they will likely be facedwithissueslikefurnacedurability,

investment, carbon footprint, and so on.

conditional

optimization,equipment