GB/T 29918-2023Rare earth-based hydrogen storage alloys—Test method for measurement of pressure-composition isotherm (PCI) (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents" Drafting.

This document replaces GB/T 29918-2013 "Method for determination of pressure-composition isotherm (PCI) of rare earth AB5 type hydrogen storage alloy" and is consistent with Compared with GB/T 29918-2013, in addition to structural adjustments and editorial changes, the main technical changes are as follows.

a) The scope of application has been changed. the pressure range of method 1 volumetric method is "0.001MPa~10MPa", and the electrochemical test method has been added.

Scope of application of the law (see Chapter 1, Chapter 1 of the 2013 edition);

b) Added requirements for reagents and materials in Method 1 (see 4.3);

c) Added parallel tests in Method 1 (see 4.5);

d) Changed the terms and data of precision of Method 1 (see 4.8, Chapter 8 of the 2013 edition);

e) Added "Method 2.Electrochemical method" (see Chapter 5);

f) Added "any circumstances that may affect the results" in the test report [see Chapter 6 k), Chapter 9 of the 2013 edition].

This document is proposed and coordinated by the National Rare Earth Standardization Technical Committee (SAC/TC229).

1 Scope

This document specifies the pressure-composition isotherm (PCI) test method for rare earth hydrogen storage alloys.

This document is applicable to the pressure-composition isotherm (PCI) test of rare earth hydrogen storage alloys.

This document contains 2 test methods. Method 1 Volume method, measuring pressure range. 0.001MPa~10MPa; Method 2 Electrochemistry Method, the measurement range is rare earth hydrogen storage alloys whose platform pressure is lower than the local atmospheric pressure 0.01MPa.

2 Normative reference documents

The contents of the following documents constitute essential provisions of this document through normative references in the text. Among them, the dated quotations For undated referenced documents, only the version corresponding to that date applies to this document; for undated referenced documents, the latest version (including all amendments) applies to this document.

GB/T 3634.2 Hydrogen Part 2: Pure hydrogen, high-purity hydrogen and ultra-pure hydrogen

GB/T 4842 Argon

GB/T 4844 Pure helium, high-purity helium and ultra-pure helium

GB/T 6003.1-2022 Technical requirements and inspection of test sieves Part 1: Wire braided mesh test sieves

GB/T 6379.2 Accuracy of measurement methods and results (correctness and precision) Part 2: Determination of repeatability of standard measurement methods Basic methods of sex and reproducibility

GB/T 6682 Specifications and test methods for water used in analytical laboratories

GB/T 7160 Nickel carbonyl powder

GB/T 8170 Numerical rounding rules and representation and determination of limit values

GB/T 15676 Rare earth terminology

GB/T 26412 Metal hydride-nickel battery negative electrode rare earth AB5 type hydrogen storage alloy powder

GB/T 31963 Metal hydride-Rare earth magnesium superlattice hydrogen storage alloy powder for negative electrode of nickel battery

YS/T 376 physically pure platinum wire

YS/T 484 Determination of specific capacity of hydrogen storage alloy for negative electrode of metal hydride nickel battery

3 Terms and definitions

The terms and definitions defined in GB/T 15676 apply to this document.

4 Method 1.Volume method