Low-frequency vibrational spectroscopy: a new tool for revealing crystalline magnetic structures in iron phosphate crystals

2021 ◽  
Vol 23 (39) ◽  
pp. 22241-22245
Author(s):  
Zihui Song ◽  
Xudong Liu ◽  
Anish Ochani ◽  
Suling Shen ◽  
Qiqi Li ◽  
...  

In this report, the strong-dependence of low-frequency (terahertz) vibrational dynamics on weak and long-range forces in crystals is leveraged to determine the bulk magnetic configuration of iron phosphate – a promising material for cathodes in lithium ion batteries.

2020 ◽  
Vol 32 (12) ◽  
pp. 2982-2999
Author(s):  
Zolani Myalo ◽  
Chinwe Oluchi Ikpo ◽  
Assumpta Chinwe Nwanya ◽  
Miranda Mengwi Ndipingwi ◽  
Samantha Fiona Duoman ◽  
...  

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 149
Author(s):  
Alexandra Holzer ◽  
Stefan Windisch-Kern ◽  
Christoph Ponak ◽  
Harald Raupenstrauch

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.


Batteries ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 36
Author(s):  
Erik Goldammer ◽  
Julia Kowal

The distribution of relaxation times (DRT) analysis of impedance spectra is a proven method to determine the number of occurring polarization processes in lithium-ion batteries (LIBs), their polarization contributions and characteristic time constants. Direct measurement of a spectrum by means of electrochemical impedance spectroscopy (EIS), however, suffers from a high expenditure of time for low-frequency impedances and a lack of general availability in most online applications. In this study, a method is presented to derive the DRT by evaluating the relaxation voltage after a current pulse. The method was experimentally validated using both EIS and the proposed pulse evaluation to determine the DRT of automotive pouch-cells and an aging study was carried out. The DRT derived from time domain data provided improved resolution of processes with large time constants and therefore enabled changes in low-frequency impedance and the correlated degradation mechanisms to be identified. One of the polarization contributions identified could be determined as an indicator for the potential risk of plating. The novel, general approach for batteries was tested with a sampling rate of 10 Hz and only requires relaxation periods. Therefore, the method is applicable in battery management systems and contributes to improving the reliability and safety of LIBs.


2006 ◽  
Vol 973 ◽  
Author(s):  
Shijun Wang ◽  
M. Stanley Whittingham

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.


Author(s):  
Olivia Long ◽  
Gopalakrishnan Sai Gautam ◽  
Emily Ann Carter

We benchmark calculated interlayer spacings, average topotactic voltages, thermodynamic stabilities, and band gaps in layered lithium transition-metal oxides (TMOs) and their de-lithiated counterparts, which are used in lithium-ion batteries as...


2012 ◽  
Vol 28 (09) ◽  
pp. 2084-2090 ◽  
Author(s):  
WANG Zhen-Po ◽  
◽  
LIU Wen ◽  
WANG Yue ◽  
ZHAO Chun-Song ◽  
...  

2017 ◽  
Vol 80 (10) ◽  
pp. 171-182
Author(s):  
Ethan Paharik ◽  
Patrick Cantwell ◽  
Gary Koenig

2019 ◽  
Vol 300 ◽  
pp. 18-25 ◽  
Author(s):  
Hye-Jung Kim ◽  
Geun-Hyeong Bae ◽  
Sang-Min Lee ◽  
Jou-Hyeon Ahn ◽  
Jae-Kwang Kim

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