High power electrode materials

Patent metadata

Field	Value
Publication number	US-9660267-B2
Application number	US-201514641172-A
Country	US
Kind code	B2
Filing date	Mar 6, 2015
Priority date	Sep 18, 2009
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

An LFP electrode material is provided which has improved impedance, power during cold cranking, rate capacity retention, charge transfer resistance over the current LFP based cathode materials. The electrode material comprises crystalline primary particles and secondary particles, where the primary particle is formed from a plate-shaped single-phase spheniscidite precursor and a lithium source. The LFP includes an LFP phase behavior where the LFP phase behavior includes an extended solid-solution range.

First claim

The invention claimed is:

1. A crystalline spheniscidite material for synthesizing lithium iron phosphate for use in an electrode, comprising:
from about 25 wt. % to about 30 wt. % iron;
from about 15 wt. % to about 20 wt. % phosphorous; and
from about 4.6 wt. % to about 5.0 wt. % ammonium;
wherein a molar ratio of phosphorus to iron is from about 1 to about 1.25;
wherein the crystalline spheniscidite material is an ammonium iron phosphate substantially free of impurities;
wherein the ammonium iron phosphate has a formula of NH 4 Fe 2 (PO 4 ) 2 OH*2H 2 O; and
wherein the crystalline spheniscidite material has a plate-shape morphology.

2. The crystalline spheniscidite material of claim 1 , wherein the crystalline spheniscidite material is a single-phase.

3. The crystalline spheniscidite material of claim 1 , wherein the crystalline spheniscidite material has a surface area in a range of 20 m 2 /g to 25 m 2 /g.

4. The crystalline spheniscidite material of claim 1 , wherein an XRD includes no impurity peaks over 2%.

5. The crystalline spheniscidite material of claim 1 , wherein an XRD includes no impurity peaks over 5%.

Assignees

• A123 Systems Llc

Inventors

• Beck Larry
• Wilson Jennifer
• Xu Chuanjing
• Shi Zhong-You
• Hammoud Maha

Classifications

• C01P2004/24

  Nanoplates, i.e. plate-like particles with a thickness from 1-100 nanometer · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title

• C01P2004/64

  Nanometer sized, i.e. from 1-100 nanometer · CPC title

• C01P2004/32

  Spheres · CPC title