GB/T 30835-2014Lithium iron phosphate-carbon composite cathode materials for lithium ion battery (English PDF)

3.1 Lithium iron phosphate-carbon composite cathode materials

Lithium-ion battery cathode material composed of lithium iron phosphate and carbon with an olivine structure. Lithium iron phosphate belongs to the orthorhombic crystal system. It has a one-dimensional lithium embedded channel.

4.1 Product classification

Lithium iron phosphate-carbon composite cathode materials are divided into energy type and power type according to charge and discharge characteristics and usage requirements, represented by LFP@C-E and LFP@C-P respectively.

5.1 Appearance

The product appearance shall be gray, black or brown powder with uniform color and no lumps.

5.2 Performance requirements

The physical and chemical properties, electrochemical properties and restricted substance content of lithium iron phosphate-carbon composite cathode materials for lithium ion battery shall comply with the provisions of Table 2.

6.1 Appearance

Visually observe under natural light conditions.

6.2 Particle size D50

Determine according to the determination method specified in GB/T 19077.1.

6.3 Moisture content

Determine the moisture content according to the method specified in GB/T 6283 for direct potentiometric titration.

6.5 BET specific surface area

The BET specific surface area of powder is measured according to the volumetric method specified in GB/T 19587.

6.6 Tap density

Measure according to the measurement method specified in GB/T 5162.

6.7 Powder compacted density

The measurement is carried out according to the measurement method specified in Annex L of GB/T 24533-2009.

6.13 Iron ion dissolution rate

Measure according to the measurement method specified in Annex E.

6.14 First coulombic efficiency

Measure according to the measurement method specified in Annex F.

6.15 First reversible specific capacity

Measure according to the measurement method specified in Annex F.

6.16 Rate performance

Measure according to the measurement method specified in Annex F.

6.17 Conductivity

Measure according to the measurement method specified in Annex G.

6.18 Restricted substance content

The measurement is carried out according to the measurement method specified in IEC 62321.

7.1 Sampling method

7.1.1 Sampling

7.1.1.1 Lithium iron phosphate-carbon composite cathode materials for bagged lithium-ion batteries shall be sampled in accordance with GB/T 13732. Open the bag of lithium iron phosphate-carbon composite cathode material to be collected in a dry environment.

Use a clean stainless steel sampling drill to insert into the bag along the axis. The insertion depth shall not be less than 4/5 of the depth of the sampling bag. Samples are taken within 20 mm around the central axis of the material in the bag.

7.1.2 Sample label

After the sample is placed in the PVC sample jar, a label is immediately attached to the outer wall. The label includes the following. […]

7.1.3 Storage of samples

7.1.3.1 Samples shall be sealed and stored in anti-breakage bags, rain-proof, moisture-proof and other environments.

7.2 Inspection

7.2.1 Exit-factory inspection

Inspect the particle size, carbon content, moisture content, BET specific surface area, tap density, electrochemical performance, iron ion dissolution amount, conductivity and other indicators of each batch of samples. They can be shipped only after passing the inspection.

7.3 Acceptance rules

7.3.1 Products that meet all the technical indicators required by a certain category in Table 2 are qualified products. If an indicator fails to meet the requirements of this category, double samples shall be taken from the sampling bags of the same batch of products to re-inspect the unqualified items.

7.3.2 The inspection department of the manufacturer shall ensure that the products shipped meet the requirements of this Standard. When each batch of products leaves the factory, a product quality inspection report is sent to the recipient.

7.3.3 The consignee has the right to accept products in accordance with this Standard and the right to reject products that do not meet the requirements of this Standard.