Lithium-ion batteries and Safety

Sissel Forseth, Sandefjord 28.04.15 Sissel.Forseth@FFI.no

Lay out

•  FFI ( Norwegian Defence Research Establishment)

•  Power source group at FFI

•  Motivation – increased usage of Li-ion batteries and reported incidents

•  Electrical battery in general and Li-ion in particular

•  Recycling and second life, some issues

FFI’s mission •  Provide science and technology advice

to the MoD and the Armed forces

•  Carry out research and development and analysis in support of future force structures

•  Undertake development of weapons and equipment as a basis for a competitive national defence industry

•  Provide science based assistance to all aspects of future force development and to current operations

•  Engage in international collaborations with partners in the defence sector

•  Investigate geophysical areas of importance to defence

•  Contribute to the national scientific and technical community, and to industrial development in general.

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Scenario development Defence analysis Concept development Operational analysis Studies of cost effectiveness Logistics Modelling and simulation Synthetic environment training Industrial strategy

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Information infrastructure Command and decision support Communication systems Information security Information operations

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Control and warning Sensor collection and fusion Situational awareness Battle space assessment Electronic support measures

FFI’s areas of research

Key figurs 2013

•  705 man years, of which 523 are research man years

•  165 ongoing research projects, 37 launched and 37 completed (187 smaller commissions)

•  388 FFI publications

•  284 papers published externally

•  633 presentations and talks by FFI employees

•  82 professional and project-related seminars organised by FFI, both in Norway and abroad

•  FFI cited or mentioned in the public media in Norway on 2339 occasions

and 422 in social media

FFI POWER SOURCES GROUP

FFI Power sources group Activity

NAVY Activity

AUV / HUGIN SUBMARINE/AIP

ARMY Activity

VEHICLE SOLIDER

CIVILIAN Activity

A safe Society– One of FFIs mandates

•  Norsk forum for batterisikkerhet (Norwegian forum for through life battery safety)

•  An informal forum for users of high energy batteries (Li and Li-ion) and relevant government bodies

•  Information sharing on safety aspects during usage, transportation and destruction

•  Two meetings pro anno – FFI is the secretary

•  Life and safety for Li-ion batteries in Maritime conditions (SafeLiLife) •  Background:

–  Electrification with Li-ion batteries is a global trend. Now it is the maritime sector`s turn.

–  Safety of Li-ion batteries is an important issue. Based on the large amounts of energy in a 1 MWh maritime battery, it is absolutely vital that safety of the battery system is assured.

–  The degradation and ageing of Li-ion batteries could affect the safety performance of batteries as well.

–  Knowledge and the ability to predict capacity decay and battery state of health will be vital information to enable safe and long-life operation of marine battery systems

•  R Partners: IFE; NTNU, HiST, FFI •  Supported by the Norwegian Research Council and Maritime

Industry

SafeLiLife Entirely civilian project

Motivation – increased usage of Li-ion batteries and reported incidents

Focus is on rechargeable Li-batteries

•  50 000 electrical cars in Norway and electrification of maritime sector has started.

•  A lot of Li-ion batteries with varying state of health and energy content will have to be handled.

•  Also done work on primary Li-batteries, see link http://www.ffi.no/no/Forskningen/Avdeling-Maritime-systemer/NFB/Sider/Batterisikkerhet.aspx

Lithium ion batteries – a controlled bomb?

•  The energy density of TNT 1.86 kWh/litre

•  The energy density of advanced batteries is 0.350 kWh/litre

•  The energy density of chocolate is 6.1 kWh/litre

High energy density is not an inherent risk by it self, but safe and economical use of these batteries requires knowledge of their particularities.

Safety is important through out the entire battery lifetime

Some incidents invovling Lithium ion batteries Event Date Chemistry Event Cause Tesla Model S 2013 Probably

NCA Fire Mechanical

impact

Dreamliner Boeing

2013 LCO Smoke and fire Probably internal cell short

Dreamliner Boeing

2013 LCO Smoke Probably internal cell short

Campbell Foss Corvus Tug

2013 NMC Fire Overcharge

Fisker Karma 2012 LiFePO4 Fire Overload due to flooding

GM Lab 2011 LiFePO4

Fire/explosion Abusive thermal cycling test

Volt 2011 NMC Fire Cell shorting after crash test

FISKER KARMA EV fire 2012

Due to flooding the battery electronic shorted, irregular discharging of the battery led to fire.

BOEING DREAMLINER B787: 3 fires

Most likely caused by internal short

Massive internal short of the battery caused by road side debire.

TESLA-S fire November 2013

The number of Li-ion cells that is produced pro anno is about 5 billions (2014) The number of incidents which can be related to defects in the cells divided by the number of cells produced is in the ppm-range

But the consequences of an incident could be large especially when large high energy batteries are involved.

Under «normal» operational conditions the probability of an unwanted incident is low

But keep in mind that old and well known batteries are not entirely harmless.

Pb and NiMH The electrolytes are corrosive and etching and under certain conditions the batteries evolve hydrogen.

What is an electrical battery? What is a Li-ion battery? Safety and Li-ion battery

The first battery

•  Clay pot, Cu cylinder and an Fe rod , the pot sealed by asphalt

•  The electrolyte, e.g. vinegar

•  Cell voltage 1.1 V

•  Usage not known

•  Found close to Bagdad

•  Produced - 250 B.C to 640 AD

•  A device which transforms chemical energy to electrical energy.

•  Main components: Anode, Cathode, Electrolyte, Container

•  If the electrolyte is a liquid a separator is needed to prevent short circuit

•  A battery - cells in series or parallel or both series and parallel

•  rechargeable and non-rechargeable

•  Different shapes, sizes and capacities

What is an electrical battery?

load

Anode

Cathode

Electrolyte

cations

anions

•  Cathode (+): Lithium-metal oxide, different compositions

•  Electrolyte: Organic liquid, e.g. DMC,EC and LiPF6 ++

•  Anode (-) : Must frequently used is carbon

•  Separator: Most frequently used is PE, PP

•  Current collectors: Al og Cu

Lithium ion cell – principal sketch

DMC: dimetylkarbonat, EC: Etylenkarbonat, PE: polyetylen, PP: polypropylen

Why Li-ion – it is all about energy density

Challenge - High energy density and flammable materials

Incidents and factors which could result in thermal runaway

Defenition «Thermal runaway» A reaction with a self heating rate larger than 10 °C/min

Calculated contributions to total energy release from 18650 cells employing different cathodes

B Barnett et al., TIAX

18 mm

Gases formed during combustion of an typical electrolyte

Toxic and irritating. Additionally small quantities of is formed.

Abuse Response of 18650 Li-Ion Cells with Different Cathodes Using EC:EMC/LiPF6 and EC:PC:DMC/LiPF6 Electrolytes. Rothe, E.P. 19, s-l.: ESC Translations, 2008, Vol.11, pp.19-41. 10.1149/1.2897969 ARC: Adiabatic reaction calorimeter

When the battery is e g in a car it is well mangaged – but what if there is a crash?

BMS: BATTERY MANAGEMENT SYSTEM

intelligent battery design

surroundings

BMS

, fus

es

A crash could result in an explosive fire

Fire and Li-ion batteries

•  Oxygen – could be liberated from the cathode

•  Combustible materials – e g the organic electrolyte (as diesel)

•  Heat – from the cell it self or external

source •  «Thermal runaway» possible from 180 oC

•  Cells could disintegrate and release fragments and flameable and toxic gases

Fire and Li-ion batteries

Fire extinguishing medium: A lot of water or heavy foam:

•  The cathode produces oxygen

•  Ejection/ explosion

•  Reignition

Recycling and second life, some issues

Recycling and second life, some issues

Lading fra el-nett Lading fra el-nett

Lading av ferge Lading av ferge

mWh – Wh, private use kWh, private use

MWh – professional use

Many types of Li-ion batteries with different properties

Second life, dismantling and recycling – ideally the battery history should be known

Recycling •  The battery packs have to be opened

–  An instruction movie has been produced by AS Batteriretur and Vestack Batteries AS

•  Opening of cells, depending on size and type – a risky business –  If possible discharge the cells –  Where to cut – X-ray CT very useful J –  Toxic,flammable liquids and fumes – ventilated area, protective clothing

etc.

18650 cell – negative and positive side

Aging and safety - unresolved issue

•  How do the safety properties change when aged and used?

–  Some on going activities in the scientific community but the results so fare are inconclusive.

–  Hopefully we will be able to give some answers due to our involvement in the SafeLiLife-project

Second life

•  For larger batteries - could be worth while if the safety properties are not negatively influenced by aging and usage

•  Larger batteries should only be handled by professionals e.g. no battery packs in the basement of a private home

Thank you very much for the attention