IEC TS 62565-5-3:2025

IEC TS 62565-5-3 ®
Edition 1.0 2025-04
TECHNICAL
SPECIFICATION
Nanomanufacturing – Product specification –
Part 5-3: Nanoenabled energy storage – Blank detail specification: silicon
nanosized materials for the negative electrode of lithium-ion batteries

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IEC TS 62565-5-3 ®
Edition 1.0 2025-04
TECHNICAL
SPECIFICATION
Nanomanufacturing – Product specification –

Part 5-3: Nanoenabled energy storage – Blank detail specification: silicon

nanosized materials for the negative electrode of lithium-ion batteries

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 07.120  ISBN 978-2-8327-0291-8

– 2 – IEC TS 62565-5-3:2025 © IEC 2025
CONTENTS
FOREWORD . 6
INTRODUCTION . 8
1 Scope . 9
2 Normative references . 9
3 Terms and definitions . 11
3.1 General terms . 11
3.2 General product description and procurement information . 11
3.3 Physical key control characteristics . 11
3.4 Chemical key control characteristics . 12
3.5 Electrochemical key control characteristics . 14
3.6 Structural key control characteristics . 15
3.7 Measurement methods . 16
4 General introduction regarding measurement methods . 19
5 Specification format . 20
5.1 General product description and procurement information . 20
5.2 Physical key control characteristics . 21
5.3 Chemical key control characteristics . 21
5.4 Electrochemical key control characteristics . 22
5.5 Structural key control characteristics . 23
6 Overview of test methods . 23
Annex A (normative) Information for standardized KCC measurement procedures . 28
A.1 General . 28
A.2 Apparent density: Oscillating funnel method . 28
A.2.1 General. 28
A.2.2 Measurement standard . 28
A.2.3 Adaptations and modifications required . 28
A.3 Tap density: Tapping apparatus . 29
A.3.1 General. 29
A.3.2 Measurement standard . 29
A.3.3 Adaptations and modifications required . 29
A.4 Compacted density: Powder compaction method. 29
A.4.1 General. 29
A.4.2 Measurement standard . 29
A.4.3 Adaptations and modifications required . 29
A.5 True density: GD . 30
A.5.1 General. 30
A.5.2 Measurement standard . 30
A.5.3 Adaptations and modifications required . 30
A.6 Powder conductivity: Four-point probe . 30
A.6.1 General. 30
A.6.2 Measurement standard . 30
A.6.3 Adaptations and modifications required . 31
A.7 Particle size distribution: LD . 31
A.7.1 General. 31
A.7.2 Measurement standard . 31
A.7.3 Adaptations and modifications required . 31

A.8 Particle shape: SEM . 31
A.8.1 General. 31
A.8.2 Measurement standard . 32
A.8.3 Adaptations and modifications required . 32
A.9 Ignition temperature: DSC . 32
A.9.1 General. 32
A.9.2 Measurement standard . 32
A.9.3 Adaptations and modifications required . 32
A.10 Silicon content: XRF . 32
A.10.1 General. 32
A.10.2 Measurement standard . 33
A.10.3 Adaptations and modifications required . 33
A.11 Carbon content: HFCIAS . 33
A.11.1 General. 33
A.11.2 Measurement standard . 33
A.11.3 Adaptations and modifications required . 33
A.12 Oxygen content: Inert gas fusion infrared detection method . 33
A.12.1 General. 33
A.12.2 Measurement standard . 33
A.12.3 Adaptations and modifications required . 33
A.13 Water content: KFC . 34
A.13.1 General. 34
A.13.2 Measurement standard . 34
A.13.3 Adaptations and modifications required . 34
A.14 Sulfur content: ICP-OES . 34
A.14.1 General. 34
A.14.2 Measurement standard . 34
A.14.3 Adaptations and modifications required . 34
A.15 Metallic impurities: ICP-AES . 35
A.15.1 General. 35
A.15.2 Measurement standard . 35
A.15.3 Adaptations and modifications required . 35
A.16 Magnetic impurities: ICP-OES . 35
A.16.1 General. 35
A.16.2 Measurement standard . 35
A.16.3 Adaptations and modifications required . 35
A.17 pH value: Potentiometry . 35
A.17.1 General. 35
A.17.2 Measurement standard . 35
A.17.3 Adaptations and modifications required . 35
A.18 Pore size distribution: GA . 36
A.18.1 General. 36
A.18.2 Measurement standard . 36
A.18.3 Adaptations and modifications required . 36
A.19 Porosity: MP . 36
A.19.1 General. 36
A.19.2 Measurement standard . 36
A.19.3 Adaptations and modifications required . 36
A.20 Specific surface area: BET . 36

– 4 – IEC TS 62565-5-3:2025 © IEC 2025
A.20.1 General. 36
A.20.2 Measurement standard . 36
A.20.3 Adaptations and modifications required . 37
A.21 Lattice spacing: TEM. 37
A.21.1 General. 37
A.21.2 Measurement standard . 37
A.21.3 Adaptations and modifications required . 37
A.22 Crystal structure: XRD . 37
A.22.1 General. 37
A.22.2 Measurement standard . 37
A.22.3 Adaptations and modifications required . 37
A.23 Elemental mapping image: EDS . 38
A.23.1 General. 38
A.23.2 Measurement standard . 38
A.23.3 Adaptations and modifications required . 38
A.24 Cross-sectional image: SEM . 38
A.24.1 General. 38
A.24.2 Measurement standard . 38
A.24.3 Adaptations and modifications required . 38
Annex B (informative) Guidance for KCC measurement procedures if no standard is
available . 39
B.1 General . 39
B.2 Amorphous degree: Raman . 39
B.2.1 General. 39
B.2.2 Good practice guide – Standard operation procedure 1 . 39
B.2.3 Measurement procedure . 39
B.3 Chemical state: XPS . 39
B.3.1 General. 39
B.3.2 Good practice guide – Standard operation procedure 2 . 39
B.3.3 Measurement procedure . 39
B.4 Specific discharge capacity: Coin cell method . 40
B.4.1 General. 40
B.4.2 Good practice guide – Standard operation procedure 1 . 40
B.4.3 Measurement procedure . 40
B.5 Rate capability: Coin cell method . 40
B.5.1 General. 40
B.5.2 Good practice guide – Standard operation procedure 1 . 40
B.5.3 Measurement procedure . 41
B.6 Coulombic efficiency: Coin cell method . 41
B.6.1 General. 41
B.6.2 Good practice guide – Standard operation procedure 1 . 41
B.6.3 Measurement procedure . 41
B.7 Cycle performance: Coin cell method . 41
B.7.1 General. 41
B.7.2 Good practice guide – Standard operation procedure 1 . 42
B.7.3 Measurement procedure . 42
B.8 Impedance: EIS . 42
B.8.1 General. 42
B.8.2 Good practice guide – Standard operation procedure 1 . 42

B.8.3 Measurement procedure . 42
B.9 Electrochemical expansion ratio: Expansion method. 43
B.9.1 General. 43
B.9.2 Good practice guide – Standard operation procedure 1 . 43
B.9.3 Measurement procedure . 43
Bibliography . 44

Table 1 – Format for general product description and procurement information . 20
Table 2 – Format for physical key control characteristics . 21
Table 3 – Format for chemical key control characteristics . 22
Table 4 – Format for electrochemical key control characteristics . 22
Table 5 – Format for structural key control characteristics . 23
Table 6 – Overview of measurement methods . 25

– 6 – IEC TS 62565-5-3:2025 © IEC 2025
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
NANOMANUFACTURING – PRODUCT SPECIFICATION –

Part 5-3: Nanoenabled energy storage – Blank detail specification: silicon
nanosized materials for the negative electrode of lithium-ion batteries

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as "IEC Publication(s)"). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC TS 62565-5-3 has been prepared by IEC technical committee 113: Nanotechnology for
electrotechnical products and systems. It is a Technical Specification.
The text of this Technical Specification is based on the following documents:
Draft Report on voting
113/842/DTS 113/879/RVDTS
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this Technical Specification is English.

This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts in the IEC 62565 series, published under the general title Nanomanufacturing –
Product specification, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
– 8 – IEC TS 62565-5-3:2025 © IEC 2025
INTRODUCTION
This document specifies how to report various characteristics of silicon nanosized materials for
the negative electrode for industrial use in electrotechnical products, and how to incorporate
these characteristics into a bilateral detail specification between vendor and user.
Lithium-ion batteries have been widely employed in the fields of portable devices, power tools,
electric vehicles and energy storage systems. Graphite, silicon-carbon composite, silicon
monoxide, lithium titanate, soft carbon, hard carbon, metal oxides and other materials can be
used as negative active materials for lithium-ion batteries. Currently, the most widely
commercialized negative active material is graphite, which has many advantages such as low
lithiation potential, high conductivity, low volume expansion and stable cycle performance.
However, the capacity of graphite is only 372 mAh/g and unable to meet the increasing demand
for high energy density. Therefore, it is essential to develop new negative active materials with
high capacity.
The theoretical capacity of silicon negative active material is 4 200 mAh/g, which is ten times
higher than that of graphite. However, it has disadvantages of huge volume expansion and low
electronic conductivity, resulting in poor cycle performance. Massive efforts have been devoted
to solve these problems, including:
a) controlling the size of Si particles (e.g. using silicon nanosized material);
b) combining Si with carbon or other materials since carbon can form a conductive network
and buffer the expansion of Si;
c) enhancing the stability of the interface between Si and electrolyte by using new binders or
electrolyte additives.
Silicon nanosized materials for the negative electrode have advantages of high capacity, high
safety and abundant raw materials. Different kinds of methods have been explored to prepare
silicon nanosized materials for the negative electrode in universities, institutes and industries.
Silicon nanosized materials for the negative electrode with different morphology or structure
can lead to distinct differences in physical and chemical performance. More effort and
investment are needed in order to further understand the properties of silicon nanosized
materials for the negative electrode.
The method of combining silicon nanosized material with carbon is regarded as one of the most
effective ways to release the stress induced by the expansion upon lithiation/delithiation
process, avoiding the fracture and pulverization of Si particles. Si-C negative active material
has been commercialized for several years. Though the problem of expansion is partially
resolved, it remains the key factor that prevents silicon from large-scale commercial
applications. At the same time, the demand for silicon nanosized materials for the negative
electrode is growing rapidly. Therefore, it is essential to standardize a blank detail specification
of characterization techniques and measurement methods for the properties of silicon
nanosized materials for the negative electrode.
In this document, the key physical, chemical, electrochemical and structural characteristics that
will significantly influence the performance of silicon nanosized materials for the negative
electrode are listed, as well as those corresponding measurement methods. Furthermore,
characterization techniques and measurement methods for particular properties of silicon
nanosized materials for the negative electrode which need to be standardized are summarized
in a matrix form. The matrix can serve as a guide for developing necessary International
Standards on characterization and measurements of silicon nanosized materials for the
negative electrode and related silicon-based negative active materials.

NANOMANUFACTURING – PRODUCT SPECIFICATION –

Part 5-3: Nanoenabled energy storage – Blank detail specification: silicon
nanosized materials for the negative electrode of lithium-ion batteries

1 Scope
This part of IEC 62565, which is a Technical Specification, establishes a standardized method
to determine a blank detail specification (BDS) for
• silicon nanosized materials
used for
• negative electrode of lithium-ion batteries.
This document is intended to be used for silicon nanosized materials for the negative electrode
of lithium-ion batteries which have been widely employed in the fields of
– portable devices,
– power tools,
– electric vehicles, and
– energy storage system.
Numeric values for the key control characteristics are left blank as they will be specified
between customer and supplier in the detail specification (DS). In the DS key control
characteristics can be added or removed if agreed between customer and supplier.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC TS 62607-4-2:2016, Nanomanufacturing – Key control characteristics – Part 4-2: Nano-
enabled electrical energy storage – Physical characterization of cathode nanomaterials, density
measurement
IEC TS 62607-4-7:2018, Nanomanufacturing – Key control characteristics – Part 4-7: Nano-
enabled electrical energy storage – Determination of magnetic impurities in anode
nanomaterials, ICP-OES method
IEC TS 62607-4-8:2020, Nanomanufacturing – Key control characteristics – Part 4-8: Nano-
enabled electrical energy storage – Determination of water content in electrode nanomaterials,
Karl Fischer method
IEC TS 62607-6-1:2020, Nanomanufacturing – Key control characteristics – Part 6-1:
Graphene-based material – Volume resistivity: four probe method
ISO 3923-1:2018, Metallic powders – Determination of apparent density – Part 1: Funnel
method
– 10 – IEC TS 62565-5-3:2025 © IEC 2025
ISO 3953:2011, Metallic powders – Determination of tap density
ISO 9277:2022, Determination of the specific surface area of solids by gas adsorption – BET
method
ISO 9516-1:2003, Iron ores – Determination of various elements by X-ray fluorescence
spectrometry – Part 1: Comprehensive procedure
ISO/TS 10797:2012, Nanotechnologies – Characterization of single-wall carbon nanotubes
using transmission electron microscopy
ISO 11357-5:2013, Plastics – Differential scanning calorimetry (DSC) – Part 5: Determination
of characteristic reaction-curve temperatures and times, enthalpy of reaction and degree of
conversion
ISO 12154:2014, Determination of density by volumetric displacement – Skeleton density by
gas pycnometry
ISO 13320:2020, Particle size analysis – Laser diffraction methods
ISO 15202-3:2004, Workplace air – Determination of metals and metalloids in airborne
particulate matter by inductively coupled plasma atomic emission spectrometry – Part 3:
Analysis
ISO 15350:2000, Steel and iron – Determination of total carbon and sulfur content – Infrared
absorption method after combustion in an induction furnace (routine method)
ISO 15632:2021, Microbeam analysis – Selected instrumental performance parameters for the
specification and checking of energy-dispersive X-ray spectrometers (EDS) for use with a
scanning electron microscope (SEM) or an electron probe microanalyser (EPMA)
ISO 15901-1:2016, Evaluation of pore size distribution and porosity of solid materials by
mercury porosimetry and gas adsorption – Part 1: Mercury porosimetry
ISO 15901-2:2022, Pore size distribution and porosity of solid materials by mercury porosimetry
and gas adsorption – Part 2: Analysis of nanopores by gas adsorption
ISO 17053:2005, Steel and iron – Determination of oxygen – Infrared method after fusion under
inert gas
ISO 19396-1:2017, Paints and varnishes – Determination of pH value – Part 1: pH electrodes
with glass membrane
ISO 19749:2021, Nanotechnologies – Measurements of particle size and shape distributions by
scanning electron microscopy
ISO 20720:2018, Microbeam analysis – Methods of specimen preparation for analysis of
general powders using WDS and EDS
ISO 22036:2024, Environmental solid matrices – Determination of elements using inductively
coupled plasma optical emission spectrometry (ICP-OES)
EN 13925-2:2003, Non-destructive testing – X-ray diffraction from polycrystalline and
amorphous materials – Part 2: Procedures

3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1 General terms
3.1.1
key control characteristic
KCC
material property or intermediate product characteristic which can affect safety or compliance
with regulations, fit, function, performance, quality, reliability or subsequent processing of the
final product
Note 1 to entry: The measurement of a key control characteristic is described in a standardized measurement
procedure with known accuracy and precision.
Note 2 to entry: It is possible to define more than one measurement method for a key control characteristic if the
correlation of the results is well-defined and known.
Note 3 to entry: The terms "key performance indicator" and "property" shall not be used to indicate the special
meaning of key control characteristic with respect to a blank detail specification.
[SOURCE: IEC TS 62565-5-2:2022 [1], 3.1.4, modified – The admitted term "key performance
indicator" has been deleted and Note 3 to entry has been added.]
3.1.2
blank detail specification
BDS
structured generic specification of the set of key control characteristics which are needed to
describe a specific nano-enabled product without assigning specific values and/or attributes
Note 1 to entry: The templates defined in a blank detail specification list the key control characteristics for the nano-
enabled material or product without assigning specific values to it.
Note 2 to entry: Examples of nano-enabled products are: nanomaterials, nanocomposites and nano-subassemblies.
Note 3 to entry: Blank detail specifications are intended to be used by industrial users to prepare their detail
specifications used in bilateral procurement contracts. A blank detail specification facilitates the comparison and
benchmarking of different materials. Furthermore, a standardized format makes procurement more efficient and more
error robust.
[SOURCE: IEC TS 62565-5-2:2022 [1], 3.1.5]
3.2 General product description and procurement information
3.2.1
silicon nanosized material for the negative electrode
negative active material for lithium-ion batteries which contains silicon nanosized particles
3.3 Physical key control characteristics
3.3.1
apparent density
dry mass per unit volume of a powder obtained by free pouring under specified conditions
[SOURCE: ISO 9161:2019 [2], 3.1]

– 12 – IEC TS 62565-5-3:2025 © IEC 2025
3.3.2
tap density
dry mass per unit volume of a powder in a container that has been tapped under specified
conditions
[SOURCE: ISO 9161:2019 [2], 3.2]
3.3.3
compacted density
ratio of the mass of powder to the volume it occupies after it has been subjected to compression
under a certain pressure
[SOURCE: IEC TS 62607-4-2:2016, 3.1.2]
3.3.4
true density
ratio between sample mass and the volume of the sample including the volume of closed pores
(if present) but excluding the volumes of open pores as well as that of void spaces between
particles within the bulk sample
[SOURCE: ISO 12154:2014, 3.3, modified – The term "skeleton density" has been replaced by
"true density".]
3.3.5
powder conductivity
ability of powder to conduct electrical current
3.3.6
particle size distribution
cumulative distribution of particle concentration as a function of particle size
[SOURCE: ISO 14644-1:2015 [3], 3.2.4]
3.3.7
particle shape
external geometric form of a particle
Note 1 to entry: Shape description requires two scalar descriptors, i.e. length and breadth.
[SOURCE: ISO 19749:2021, 3.1.10]
3.3.8
ignition temperature
minimum temperature at which a material will ignite spontaneously under specified test
conditions
[SOURCE: ISO 8421-1:1987 [4], 1.3, modified – The term "auto-ignition temperature" has been
replaced by "ignition temperature".]
3.4 Chemical key control characteristics
3.4.1
silicon content
amount of silicon in the material as a percentage of the mass

3.4.2
carbon content
amount of carbon in the constituent, material, or product as a percentage of the mass
[SOURCE: ISO 16620-1:2015 [5], 3.1.6]
3.4.3
oxygen content
amount of oxygen in the material as a percentage of the mass
3.4.4
water content
ratio, expressed as a percentage, between the mass of water contained in the material as
received and the corresponding dry residue of the material
[SOURCE:ISO 21268-1:2019 [6], 3.6, modified – Note 1 to entry has been deleted.]
3.4.5
sulfur content
amount of sulfur element in the material as a percentage of the mass
3.4.6
metallic impurities
metals existing on or inside silicon nanosized materials for the negative electrode
3.4.7
magnetic impurities
magnetic metals existing on or inside silicon nanosized materials for the negative electrode
Note 1 to entry: Magnetic impurities can be attracted by the magnets on or inside silicon nanosized materials for
the negative electrode and the total content of iron, cobalt, chromium, nickel is calculated as magnetic impurities
existing in silicon nanosized materials for the negative electrode.
3.4.8
amorphous degree
intensity ratio of the disordered carbon and graphitized carbon in the material
Note 1 to entry: The amorphous degree can be evaluated by I /I . I /I is the intensity ratio of the D band and the
D G D G
G band. In the Raman spectroscopy test, the D band is the signal of disordered carbon caused by the structural
defects and the impurities. The G band is generated by the stretching vibration between C-C, and the G band
represents the internal vibration of the sp hybridized carbon atoms. The larger the ratio of I /I , the lower the order
D G
of the carbon material. Functional group is used to test the order of degree of carbon materials existing in the negative
active material. The ratio of the integrated area of the D band and G band (R = I /I ) reflects the graphitization
G D
degree of the carbon material. High I /I ratio of the carbon materials leads to better electrical conductivity [7].
G D
3.4.9
chemical state
state of an atom arising from its chemical interaction with neighbouring atoms in a molecule,
compound, solid, liquid, or gas that leads to a characteristic energy or feature observable in
electron spectroscopy
[SOURCE: ISO 18115-1:2023 [8], 12.23, modified – Notes 1 to 5 have been deleted.]

– 14 – IEC TS 62565-5-3:2025 © IEC 2025
3.4.10
pH value
measure of the concentration of acidity or alkalinity of a material in an aqueous solution
Note 1 to entry: The pH value is expressed on a logarithmic scale numbered from 0 to 14 with 7,0 as a neutral
point, numbers higher than 7 denoting alkalinity and numbers lower than 7 denoting acidity.
[SOURCE: ISO 5127:2017 [9], 3.12.2.29]
3.5 Electrochemical key control characteristics
3.5.1
specific discharge capacity
amount of electricity discharged from per unit mass active materials under specified test
conditions (discharge rate, temperature, termination voltage, etc.)
Note 1 to entry: Unit: milliampere hours per gram (mAh/g).
3.5.2
rate capability
ratio of capacity at certain large charge or discharge rate to the capacity at low charge or
discharge rate
3.5.3
coulombic efficiency
efficiency of the battery based on electricity (Coulomb) for a specified charge/discharge
procedure, which is expressed by output electricity divided by input electricity
[SOURCE: ISO/TR 13062:2015 [10], 2.3.3.4.1]
3.5.4
cycle performance
ratio of discharge capacity after a certain number of cycles at a certain temperature and current
rate to the capacity of the first cycle
3.5.5
impedance
effective resistance of an electric circuit or component to alternating current, arising from the
combined effects of ohmic resistance and electrochemical reaction resistance
[SOURCE: ISO/TS 21633:2021 [11], 3.8, modified – The term "electrochemical impedance" has
been replaced by "impedance". In the definition, "reactance" has been replaced with
"electrochemical reaction resistance".]
3.5.6
electrochemical expansion ratio
ratio of the thickness of the electrode after charging and discharging for a certain number of
cycles under certain temperature and current density to the initial thickness
Note 1 to entry: The electrochemical expansion includes reversible expansion and irreversible expansion. The
reversible expansion is caused by lattice expansion through lithiation, and can be retracted during delithiation. The
volume change caused by formation of solid electrolyte interface (SEI) film, irreversible damage of material structure,
failure of binder and so on cannot be retracted, which is classified into irreversible expansion.

3.6 Structural key control characteristics
3.6.1
pore size distribution
percentage by numbers or by volume of each classified pore size which exists in a material
[SOURCE: ISO 3252:2023 [12], 3.3.47]
3.6.2
porosity
ratio of the volume of the accessible pores and voids to the bulk volume occupied by an amount
of the solid
[SOURCE: ISO 15901-1:2016, 3.27]
3.6.3
specific surface area
SSA
absolute surface area of the sample divided by sample mass
[SOURC
...