EVSTF-06-05e
JRC proposal for adoption of "Venting" as a pass/fail criterion in GTR-EVS
Incorporating text from:
 Current GTR EVS draft (EVS-07-04e) - in black
 “OICA position on venting”, presentation circulated among TF3 experts on
December 9, 2015 – in red
 JRC input – in green
Text for I "Statement of technical rationale and justification ", 4.5. "Rationale for REESS
requirements"
1. Definitions of terms related to REESS requirements and its applicability:
The following terms are used for setting the pass-fail criteria of REESS requirements;
- “Electrolyte leakage” (no definition as it depends on the measurement
procedure in certain tests)
- “Venting“ (3.X)
- “Rupture” (3.31.)
- “Fire” (3.18.)
- “Explosion” (3.15.)
These terminologies, in general, correspond to the relevant industry standards and UN
Transport of Dangerous Goods, Manual of Tests and Criteria, paragraph 38.3 (UN38.3.)
2. Applicability of these criteria is considered based on the vehicle status intended for
each test scenario; e.g. under normal condition, at an accident or other unusual
circumstances, etc. For the tests simulating normal condition, all of four five criteria
shall be met, while the tests simulating an accident or unusual circumstances, only the
severer events such as Fire or Explosion are applied as the criteria.
3. “Venting”, that generally means the release of excessive internal pressure from cell
or battery in a manner intended by design to preclude rupture or explosion, is not
adopted as the criteria because venting is a safety feature to mitigate the hazard level in
the thermal event of the cell.
Text for II "Text of Regulation", 3. "Definitions"
3.X "Venting" means the release of excessive internal pressure from cell or battery in a
manner intended by design to preclude rupture or explosion.
Text for II "Text of Regulation", 5. "Performance requirements"
5.1.X.1
Under normal vehicle operation, the vehicle occupants shall not be exposed to any
hazardous environment caused by emitted gases emissions from REESS. (Same as EVS0719e)
5.1.X.1.1
For the open-type traction battery, requirement of 5.1.X.1 shall be verified by the
following test procedure.
5.1.x.1.1.1
(same as current EVS-GTR draft 5.1.Y).
5.1.x.1.2
For REESS other than open-type traction battery, the requirement of 5.1.X.1 is deemed
to be satisfied, if when no venting gas occurs is observed as verified by visual and/or
audible inspection without disassembling any part of the Tested-Device when tested
according to 6.X.X.* (based on EVS-0719e).
[5.3.2. Vibration
The test shall be conducted in accordance with paragraph 6.2.2.
During the test, there shall be no evidence of rupture (applicable to high voltage REESS
(s) only), electrolyte leakage, venting (for REESS other than open-type), fire or
explosion.
The evidence of electrolyte leakage shall be verified by visual inspection without
disassembling any part of the Tested-Device. The evidence of venting shall be verified
by visual and/or audible inspection without disassembling any part of the Tested
Device.
For a high voltage REESS, the isolation resistance measured after the test in accordance
with paragraph 6.1.1. shall not be less than 100 Ω/Volt.]
[5.3.3. Thermal shock and cycling
The test shall be conducted in accordance with paragraph 6.2.3.
During the test, there shall be no evidence of electrolyte leakage, rupture (applicable to
high voltage REESS(s) only), venting (for REESS other than open-type), fire or explosion.;
The evidence of electrolyte leakage shall be verified by visual inspection without
disassembling any part of the Tested-Device. The evidence of venting shall be verified
by visual and/or audible inspection without disassembling any part of the Tested
Device.
For a high voltage REESS, the isolation resistance measured after the test in accordance
with paragraph 6.1.1. shall not be less than 100 Ω/Volt.]
[5.3.5. External short circuit protection
The test shall be conducted in accordance with paragraph 6.2.7.
During the test there shall be no evidence of; electrolyte leakage, rupture (applicable to
high voltage REESS(s) only), venting (for REESS other than open-type), fire or explosion.
The evidence of electrolyte leakage shall be verified by visual inspection without
disassembling any part of the Tested-Device. The evidence of venting shall be verified
by visual and/or audible inspection without disassembling any part of the Tested
Device.
For a high voltage REESS, the isolation resistance measured after the test in accordance
with paragraph 6.1.1. shall not be less than 100 Ω/Volt.]
[5.3.6. Overcharge protection
The test shall be conducted in accordance with paragraph 6.2.8.
During the test there shall be no evidence of electrolyte leakage, rupture (applicable to
high voltage REESS(s) only), venting (for REESS other than open-type), fire or explosion.
The evidence of electrolyte leakage shall be verified by visual inspection without
disassembling any part of the Tested-Device. The evidence of venting shall be verified
by visual and/or audible inspection without disassembling any part of the Tested
Device.
For a high voltage REESS, the isolation resistance measured after the test in accordance
with paragraph 6.1.1. shall not be less than 100 Ω/Volt.]
[5.3.7. Over-discharge protection
The test shall be conducted in accordance with paragraph 6.2.9.
During the test there shall be no evidence of; electrolyte leakage, rupture (applicable to
high voltage REESS(s) only), venting (for REESS other than open-type), fire or explosion.
The evidence of electrolyte leakage shall be verified by visual inspection without
disassembling any part of the Tested-Device. The evidence of venting shall be verified
by visual and/or audible inspection without disassembling any part of the Tested
Device.
For a high voltage REESS, the isolation resistance measured after the test in accordance
with paragraph 6.1.1. shall not be less than 100 Ω/Volt.]
[5.3.8. Over-temperature protection
The test shall be conducted in accordance with paragraph 6.2.10.
During the test there shall be no evidence of; electrolyte leakage, rupture (applicable to
high voltage REESS(s) only), venting (for REESS other than open-type), fire or explosion.
The evidence of electrolyte leakage shall be verified by visual inspection without
disassembling any part of the Tested-Device. The evidence of venting shall be verified
by visual and/or audible inspection without disassembling any part of the Tested
Device.
For a high voltage REESS, the isolation resistance measured after the test in accordance
with paragraph 6.1.1. shall not be less than 100 Ω/Volt.]
Rationale for adoption of "Venting" as a pass/fail criterion in GTR-EVS
Venting, as defined in 3.X, may be part of a normal operation for some battery
technologies, such as e.g. for open-type batteries, or may be a signal of unintended
processes taking place as e.g. in case of Li-ion battery thermal runaway.
Toxic, corrosive and flammable gases can be emitted upon venting of batteries. For
aqueous electrolyte batteries vented gases mainly consist of hydrogen and/or oxygen,
while for non-aqueous batteries, such as e.g. Li-ion batteries, a complex mixture of
chemical substances may be vented.
Extensive research has shown that gases generated in and vented from Li-ion batteries
typically include carbon dioxide (CO2), carbon monoxide (CO), hydrogen (H2), oxygen
(O2), light C1-C5 hydrocarbons, e.g. methane and ethane, and fluorine-containing
compounds such as hydrogen fluoride (HF) and fluoro-organics such as e.g. ethyl
fluoride[1-6].
For 18650 cells, in average ca. 1.2 L of gas can be vented for each Ah of cell capacity [4].
Hazards associated with toxicity, corrosiveness and flammability of gases emitted from
batteries are recognised in various standards and regulations. For example:
ISO 6469 [7] requires that "No potentially dangerous concentration of
hazardous gases and other hazardous substances shall be allowed anywhere in
the driver, passenger and load compartments" and refers to the latest version
of applicable National/International Standards or regulations for the maximum
allowed accumulated quantity of hazardous gases and other substances.
SAE J2464 [8] requires that in hazardous substances monitoring tests both
electrolyte vapours and vented airborne volatiles and particulates are analysed.
The release of hazardous substances shall be measured and referenced to the
ERPG-2 levels [9], and to upper and lower flammability levels when mixed with
air.
SAE J2929 [10] states that consideration should be given to preventing the
build-up of these [harmful to humans] gases in sufficient concentration to be
harmful inside the passenger compartment.
UL 2580 [11] defines the limits for toxic gas release for both operational and
non-operational/crash level tests and lists analytical methods suitable for
detection and quantification of toxic emissions.
UN 38.3 [12] explicitly includes a requirement of no venting for altitude
simulation, thermal test, vibration and [mechanical] shock tests.
This regulation includes a no-fire requirement which addresses the issue of vented gas
flammability. This regulation also requires determination of hydrogen emissions during
the charge procedures of the REESS for open-type batteries, thereby addressing one of
the worst-case in-use scenarios of hydrogen gas emission for this type of REESS.
To avoid human harm that may occur from the electric power train, for REESS other
than open-type, venting is adopted as a pass/fail criterion for the following in-use tests:
vibration, thermal shock and cycling, external short circuit protection, overcharge and
over-discharge protection, over-temperature protection.
_______________________________________________
1. S. Koike, M. Shikano, H. Sakaebe, H. Kobayashi, "Study of generative gas species from lithiumion battery component under abuse conditions", Abstract # 1009, Honolulu 2012, The
Electrochemical Society Meeting.
2. M. Onuki, S. Kinoshita, Y. Sakata, M. Yanagidate, Y. Otake, M. Ue, M. Daguchi, J. Electrochem.
Soc., 2008, 155, A794.
3. C. Mikolajczak, M.Kahn, K. White, R.T. Long, "Lithium-Ion batteries hazard and use
assessment", Springer, 2011 and references therein.
4. E.P. Roth, C.J. Orendorff, "How electrolytes influence battery safety", Interface, Summer 2012,
p.45.
5. W.Kong, H.Li, X.Huang, L.Chen, J.Power Sources, 2005, 142, 285.
6. A. Hammami, N. Raymond, M. Armand, Nature, 2003, 424, 635-636.
7. ISO 6469, "Electrically Propelled Road Vehicles – Safety Specifications – Part 1: On-board
Rechargeable Energy Storage System (RESS)", SEP2009.
8. SAE J2464, "Electric and Hybrid Electric Vehicle Rechargeable Energy Storage System (RESS)
Safety and Abuse Testing", NOV2009.
9. Information on Protective Action Criteria, including a definition of ERPG levels, is available at
http://www.atlintl.com/DOE/teels/teel/search.html
10. SAE J2929, "Safety Standard for Electric and Hybrid Vehicle Propulsion Battery Systems
Utilising Lithium-based Rechargeable Cells", FEB2013.
11. UL 2580, "Standard for Safety. Batteries for Use in Electric Vehicles", DEC2013.
12. UN 38.3, "Recommendations on the Transport of Dangerous Goods. Manual of Tests and
Criteria", 6th edition, 2015.
Proposed GTR-EVS preamble wording of underlying risk/rationale for requirements
for detection and quantification of venting for tests addressing safety of REESS postcrash.
At the moment venting is not adopted as a requirement for tests addressing safety of
REESS post-crash. Accordingly, venting is allowed to occur unrestricted. Assessment of
potential safety risks of this requires more research to evaluate whether limits for
emissions are required, for which species and which technique can be used to measure
these. It was not possible to research and analyse this in Phase 1. Therefore, it will be
considered in Phase 2 of this Regulation.