GB 31241-2022Lithium ion cells and batteries used in portable electronic equipment - Safety technical specification (English PDF)

Foreword

This document was drafted in accordance with the rules given in GB/T 1.1-2020, Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents.

This document replaces GB 31241-2014 Lithium ion cells and batteries used in portable electronic equipment - Safety requirements. Compared with GB 31241-2014, in addition to structural adjustments and editorial changes, the main technical changes of this document are as follows:

a) Change the terms, as well as definitions, for lithium ion cell (see 3.1; 3.1 of the

2014 edition), lithium ion battery (see 3.2; 3.2 of the 2014 edition), upper limited charging voltage (see 3.11; 3.9 of the 2014 edition), upper limited charging temperature (see 3.23; 3.19 of the 2014 edition) and upper limited discharging temperature (see 3.25; 3.20 of the 2014 edition); add the terms and definitions of nominal voltage (see 3.7), nominal energy (see 3.9), reference test current (see 3.10), limited charging voltage (see 3.13), end of discharge voltage (see 3.14), lower limited charging temperature (see 3.24), lower limited discharging temperature (see 3.26) and allowable maximum surface temperature (see 3.27); delete the terms and definitions of gas leakage (see 3.22 of the 2014 edition) and rupture (see 3.23 of the 2014 edition);

b) Change the voltage measurement tolerance [see 4.3a); 4.3a) of the 2014 edition;

c) Change the temperature measurement method (see 4.4; 4.4 of the 2014 edition), charging and discharging procedures for test (see 4.5; 4.5 of the 2014 edition), sample requirements (see 4.7.1; 4.7.1 of the 2014 edition), sample capacity test (see 4.7.3; 4.7.3 of the 2014 edition), sample pretreatment (see 4.7.4; 4.7.4 of the 2014 edition), test items (see 4.7.5; 4.7.5 of the 2014 edition) and test sequence (see 4.7.6; 4.7.6 of the 2014 edition);

d) Change the requirements for general safety considerations (see 5.1; 5.1 of the

2014 edition), safety working parameters (see 5.2; 5.2 of the 2014 edition) and labeling and warning instructions (see 5.3; 5.3 of the 2014 edition);

e) Change the high temperature external short circuit (see 6.1; 6.1 of the 2014 edition), overcharge (see 6.2; 6.2 of the 2014 edition) and forced discharge (see 6.3; 6.3 of the 2014 edition); delete the normal temperature external short circuit (see 6.1 of the 2014 edition);

f) Change the low air pressure (see 7.1; 7.1 of the 2014 edition), temperature cycle (see 7.2; 7.2 of the 2014 edition), vibration (see 7.3; 7.3 of the 2014 edition), acceleration impact (see 7.4; 7.4 of the 2014 edition) and extrusion (see 7.6; 7.6 of the 2014 edition);

g) Change the low air pressure (see 8.1; 8.1 of the 2014 edition), temperature cycle (see 8.2; 8.2 of the 2014 edition), vibration (see 8.3; 8.3 of the 2014 edition), dropping (see 8.5; 8.5 of the 2014 edition) and flame retardant requirements (see 8.9; 8.9 of the 2014 edition);

h) Change the general (see 9.1; 9.1 of the 2014 edition), overvoltage charging (see 9.2; 9.2 of the 2014 edition), overcurrent charging (see 9.3; 9.3 of the 2014 edition), overcurrent discharging (see 9.5; 9.5 of the 2014 edition) and reverse charging (see 9.7; 9.7 of the 2014 edition); move the electrostatic discharge to sample pretreatment (see 4.7.4; 9.8 of the 2014 edition);

i) Change the general (see Chapter 10; 10.1 of the 2014 edition), overcurrent for charge protection (see 10.2; 10.3 of the 2014 edition) and overcurrent for discharge protection (see 10.4; 10.5 of the 2014 edition); delete the high voltage resistance (see 10.7 of the 2014 edition);

j) Change the general (see Chapter 11; 11.1 of the 2014 edition) and charging and discharging temperature control (see 11.5; 11.6 of the 2014 edition);

k) Change the conformance requirements (see 12.1; 12.1 of the 2014 edition) and test requirements (see 12.2; 12.2 of the 2014 edition);

l) Add the example of working range (see Appendix A), swallowing gauge test tooling (see C.1 in Appendix C), reference standard for safety-critical components (see Appendix D) and test method for flammability (see Appendix F);

m) Change the test sequence (see Appendix B; Appendix C of the 2014 edition);

n) Delete the example of quality control process requirements (see Appendix A of the 2014 edition), design and manufacturing process (see Appendix B of the 2014 edition), example of the working range of lithium cobalt oxide-graphite system cell (see Appendix D of the 2014 edition) and heavy impact test tooling (see E.1 of the 2014 edition).

Please note that some of the contents of this document may involve patents. The issuing organization of this document is not responsible for identifying patents.

This document is proposed and managed by the Ministry of Industry and Information Technology of the People's Republic of China.

The previous versions of this document and the documents which are replaced by this document are as follows:

-- This is the first revision.

Introduction

The purpose of this introduction is to introduce the principles upon which the requirements of this document are based. An understanding of these principles is necessary for the design and production of safe lithium ion cells and batteries. It should be noted that this document only considers the most basic safety requirements for lithium ion cells and batteries to provide personal and property safety protection, and does not involve performance and functional characteristics.

Further developments in technology and processes will necessarily require further revisions of this document.

Hazards posed by lithium ion cells and batteries within the scope of this document refer to:

-- Leakage, which may directly cause chemical corrosion hazards to the human body, or lead to internal insulation failure of battery-powered electronic products and indirectly cause dangers such as electric shock and fire;

-- Fire, which may directly burn the human body, or cause fire hazards to battery- powered electronic products;

-- Explosion, which may directly endanger the human body, or damage the equipment;

-- Overheating, which may directly cause burns to the human body, or cause a decrease in the insulation level and performance of safety components, or ignite flammable liquids.

Leakage hazards may be caused by breakage of the enclosure due to internal stress or external stress. Fire and explosion hazards may be caused by thermal runaway inside the cell, which may be caused by a short circuit inside the cell, a strong oxidation reaction of the cell material, etc.

When determining which design scheme is used for a cell or battery, observe the following priorities:

avoid using materials that are prone to thermal runaway;

-- Secondly, if the above principles cannot be implemented, it is necessary to design protective devices to reduce or eliminate the possibility of hazards, such as adding protective devices, etc.;

-- Finally, if none of the above-mentioned schemes and other measures can completely avoid the occurrence of hazards, take measures to identify and explain the residual hazards.

The above principles cannot replace the detailed requirements of this document, but only let designers understand the principles on which these requirements are based.

The safety of lithium ion cells and batteries is related to their material selection, design, production process, transportation and use conditions. The use conditions include normal use conditions, foreseeable misuse conditions and foreseeable failure conditions, as well as environmental conditions that affect its safety, such as temperature, altitude and other factors.

The safety requirements for lithium ion cells and batteries cover the hazards to personnel caused by all the above factors. Personnel refers to maintenance personnel and users.

Maintenance personnel refer to the maintenance personnel of electronic products and their cells; maintenance personnel can use professional skills to avoid possible injuries when there is an obvious danger. However, maintenance personnel need to be protected from unexpected dangers, for example, labeling or warning instructions shall be used to remind maintenance personnel of residual hazards.

Users refer to all personnel except maintenance personnel. Safety protection requirements are based on the assumption that users have not been trained on how to identify hazards, but they will not intentionally create dangerous situations.

1 Scope

This document specifies the safety requirements and test methods for lithium ion cells and batteries used in portable electronic equipment.

This document applies to lithium ion cells and batteries used in portable electronic equipment (hereinafter referred to as cells and batteries). Examples of portable electronic equipment within the scope of this document are as follows:

a) portable office products: laptops, tablets, etc.;

cameras, video cameras, recording pens, Bluetooth headsets, portable speakers, etc.;

consoles, e-books, power banks, portable energy storage power supplies, portable projectors, wearable devices, etc.

This document may apply, as a reference, to lithium ion cells and batteries for similar purposes to the examples above.

There may be additional requirements for lithium ion cells or batteries for portable electronic equipment used in specific occasions such as vehicles, ships, and aircraft, as well as in special fields such as medical treatment, mining, and submarine operations.

This document does not apply to lithium ion cells and batteries for electronic cigarettes.

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 version corresponding to that date is applicable to this document; for undated references, the latest version (including all amendments) is applicable to this document.

3 Terms and definitions

The following terms and definitions are applicable to this document. A device – designed to be rechargeable – that realizes the mutual conversion of chemical energy and electrical energy by relying on the movement of lithium ions between the positive and negative electrodes. A ready-to-use assembly consisting of any number of lithium ion batteries including a protective circuit. product (including its accessories). For the test of the protective circuit in the charger or electronic product (including its accessories), see Chapter 11. packaging materials, connectors, and protective devices. A mobile electronic product – not exceeding 18 kg – that is intended to be frequently carried by users. Portable electronic equipment that is intended to be held in the hand during normal use. A lithium ion battery – allowing direct user replacement – that is used in portable electronic equipment. A lithium ion cell or lithium ion battery – not allowing direct user replacement – that is built into portable electronic equipment. An appropriate approximate value that is used to identify the cell or battery voltage. The cell or battery capacity that is indicated by the manufacturer. The energy value of a cell or a battery, which is determined under specified conditions as indicated by the manufacturer. […]

4 Test conditions

5 General safety requirements

6 Electrical safety test of cell