Design of a new lithium ion battery test cell for in-situ neutron diffraction measurements

• Published in: Journal of power sources 2013-03, Vol.226, p.249-255
• Main Authors: Roberts, Matthew, Biendicho, Jordi Jacas, Hull, Stephen, Beran, Premysl, Gustafsson, Torbjörn, Svensson, Gunnar, Edström, Kristina
• Format: Article
• Language: English
• Subjects: Applied sciences; Battery; Diffraction; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Electrodes; Electrolytes; Electrolytic cells; Exact sciences and technology; In situ; LiFePO4; Lithium; Lithium-ion batteries; Materials; Neutron; Neutron diffraction; Polytetrafluoroethylenes; Silica glass
• ISSN: 0378-7753; 1873-2755; 1873-2755
• DOI: 10.1016/j.jpowsour.2012.10.085

This paper introduces a new cell design for the construction of lithium ion batteries with conventional electrochemical performance whilst allowing in situ neutron diffraction measurement. A cell comprising of a wound cathode, electrolyte and anode stack has been prepared. The conventional hydrogen-containing components of the cell have been replaced by hydrogen-free equivalents. The electrodes are fabricated using a PTFE binder, the electrolyte consists of deuterated solvents which are supported in a quartz glass fibre separator. Typical battery performance is reported using the hydrogen-free components with a specific capacity of 140 mA h g−1 being observed for LiFePO4 at a rate of 0.2 C. Neutron diffraction patterns of full cells were recorded with phase change reactions monitored. When aluminium packaging was used a better signal to noise ratio was obtained. The obtained atomic positions and lattice parameters for all cells investigated were found to be consistent with parameters refined from the diffraction pattern of a powder of the pure electrode material. This paper highlights the pertinent points in designing cells for these measurements and addresses some of the problems. [Display omitted] ► A new cell design for in situ neutron diffraction measurements of lithium ion batteries. ► Cell components are compared and a combination to provide optimal electrochemical and diffraction measurements is identified. ► Structural changes during charge and discharge of a LiFePO4 cathode are monitored. ► Patterns were refined to obtain lattice parameters and atomic positions.