State Estimation for Lithium Ion Batteries With Phase Transition Materials

Author(s):  
Shumon Koga ◽  
Leobardo Camacho-Solorio ◽  
Miroslav Krstic

Lithium Iron Phosphate (LiFePO4 or LFP) is a common active material in lithium-ion batteries. It has been observed that this material undergoes phase transitions during the normal charge and discharge operation of the battery. Electrochemical models of lithium-ion batteries can be modified to account for this phenomena at the expense of some added complexity. We explore this problem for the single particle model (SPM) where the underlying dynamic model for diffusion of lithium ions in phase transition materials is a partial differential equation (PDE) with a moving boundary. An observer is derived for the concentration of lithium ions from the SPM via the backstepping method for PDEs in a rigorous way and simulations are provided to illustrate the performance of the observer. Our comments are stated on the gap between the proposed observer and a complete state-of-charge (SoC) estimation algorithm for lithium-ion batteries with phase transition materials.

2020 ◽  
Vol 143 (4) ◽  
Author(s):  
Shumon Koga ◽  
Leobardo Camacho-Solorio ◽  
Miroslav Krstic

Abstract Lithium iron phosphate (LiFePO4 or LFP) is a common active material in lithium-ion batteries. It has been observed that this material undergoes phase transitions during the normal charge and discharge operation of the battery. Electrochemical models of lithium-ion batteries can be modified to account for this phenomenon at the expense of some added complexity. We explore this problem for the single particle model (SPM) where the underlying dynamic model for diffusion of lithium ions in phase transition materials is a partial differential equation (PDE) with a moving boundary. We derive a novel boundary observer to estimate the concentration of lithium ions together with a moving boundary radius from the SPM via the backstepping method for PDEs, and simulations are provided to illustrate the performance of the observer. Our comments are stated on the gap between the proposed observer and a complete state-of-charge (SoC) estimation algorithm for lithium-ion batteries with phase transition materials.


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.


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.


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

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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