Electrochemical study on lithium iron phosphate/hard carbon lithium-ion batteries

The bottleneck of recycling chains for spent lithium-ion batteries (LIBs) is the recovery of valuable metals from the black matter that remains after dismantling and deactivation in pre‑treatment processes, which has to be treated in a subsequent step with pyrometallurgical and/or hydrometallurgical methods. In the course of this paper, investigations in a heating microscope were conducted to determine the high-temperature behavior of the cathode materials lithium cobalt oxide (LCO—chem., LiCoO2) and lithium iron phosphate (LFP—chem., LiFePO4) from LIB with carbon addition. For the purpose of continuous process development of a novel pyrometallurgical recycling process and adaptation of this to the requirements of the LIB material, two different reactor designs were examined. When treating LCO in an Al2O3 crucible, lithium could be removed at a rate of 76% via the gas stream, which is directly and purely available for further processing. In contrast, a removal rate of lithium of up to 97% was achieved in an MgO crucible. In addition, the basic capability of the concept for the treatment of LFP was investigated whereby a phosphorus removal rate of 64% with a simultaneous lithium removal rate of 68% was observed.

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Furnace Temperature and Atmosphere Influences on Producing Lithium Iron Phosphate (LiFePO4) Powders for Lithium-Ion Batteries

Conveyor Belt Furnace Thermal Processing ◽

10.1007/978-3-319-69730-7_15 ◽

2017 ◽

pp. 113-121

Author(s):

Jinlong Xu ◽

Joyce Zhang ◽

Ken Kuang

Keyword(s):

Lithium Ion Batteries ◽

Lithium Iron Phosphate ◽

Lithium Ion ◽

Iron Phosphate ◽

Furnace Temperature

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Iron Phosphates as Cathodes of Lithium-Ion Batteries

MRS Proceedings ◽

10.1557/proc-0973-bb05-01 ◽

2006 ◽

Vol 973 ◽

Author(s):

Shijun Wang ◽

M. Stanley Whittingham

Keyword(s):

Lithium Ion Batteries ◽

Lithium Iron Phosphate ◽

Low Cost ◽

Lithium Ion ◽

Iron Phosphate ◽

Environmentally Benign ◽

Iron Phosphates ◽

Electrochemical Capacity ◽

High Theoretical Capacity ◽

Olivine Structure

ABSTRACTThis study focusses on optimizing the parameters of the hydrothermal synthesis to produce iron phosphates for lithium ion batteries, with an emphasis on pure LiFePO4 with the olivine structure and compounds containing a higher iron:phosphate ratio. Lithium iron phosphate (LiFePO4) is a promising cathode candidate for lithium ion batteries due to its high theoretical capacity, environmentally benign and the low cost of starting materials. Well crystallized LiFePO4 can be successfully synthesized at temperatures above 150 °C. The addition of a reducing agent, such as hydrazine, is essential to minimize the oxidation of ferrous (Fe2+) to ferric (Fe3+) in the final compound. The morphology of LiFePO4 is highly dependent on the pH of the initial solution. This study also investigated the lipscombite iron phosphates of formula Fe1.33PO4OH. This compound has a log-like structure formed by Fe-O octahedral chains. The chains are partially occupied by the Fe3+ sites, and these iron atoms and some of the vacancies can be substituted by other cations. Most of the protons can be ion-exchanged for lithium, and the electrochemical capacity is much increased.

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