{"id":12335,"date":"2025-05-08T15:48:43","date_gmt":"2025-05-08T19:48:43","guid":{"rendered":"https:\/\/engineering.jhu.edu\/designcenter\/?p=12335"},"modified":"2025-05-08T15:48:44","modified_gmt":"2025-05-08T19:48:44","slug":"hard-core-batteries","status":"publish","type":"post","link":"https:\/\/engineering.jhu.edu\/designcenter\/2025\/05\/08\/hard-core-batteries\/","title":{"rendered":"Hard-Core Batteries"},"content":{"rendered":"\n<p class=\"has-contrast-2-color has-text-color has-link-color has-small-font-size wp-elements-d1d4c4101d6501d379183a46dcf8f5a7\"><em>Author: <\/em>Conner Allen<\/p>\n\n\n\n<p>Senior materials science and engineering student Liam McMullin is designing a sturdier battery component for solid-state lithium batteries that could help electric vehicles and cellphones run longer between charges. His project focuses on improving the cathode\u2014a critical component inside these advanced batteries\u2014by investigating how different sizes and properties of the materials that store and transport lithium and electrolytes affect the battery\u2019s overall performance. He presented his findings on April 29 at the Whiting School of Engineering\u2019s Design Day, an annual event showcasing students\u2019 innovation and ability to translate theoretical knowledge into real-world solutions.&nbsp;<\/p>\n\n\n\n<p>\u201cTypical lithium batteries use a liquid electrolyte to move ions between the anode and cathode. Solid-state batteries use a solid material instead, which can cause the active material to crack and lose contact with the electrolyte, significantly limiting battery life,\u201d says McMullin. \u201cI\u2019m designing a new cathode to reduce this mechanical damage by optimizing the active material\u2019s particle size and the electrolytes\u2019 mechanical properties.\u201d&nbsp;<\/p>\n\n\n\n<p>McMullin is studying the internal forces that stress the battery\u2019s solid material, revealing how the mechanical forces contribute to degradation. In the lab, he used ball milling \u2014a process that grinds down a material with a ball-filled rotating cylinder\u2014along with heat treatments to create two halide electrolytes, materials commonly used in solid-state batteries, so he could experiment with them.&nbsp;<\/p>\n\n\n\n<p>After ball milling, McMullin conducted ultrasonic velocity measurements to characterize the material\u2019s mechanical properties. He used a device called an ultrasonic transreceiver which sends an acoustic wave through the material and measures how quickly it returns\u2014information that reveals information about the material\u2019s stiffness.&nbsp;&nbsp;&nbsp;<\/p>\n\n\n\n<p>\u201cThese measurements give us an idea of how much stress this material will generate in the cathode, so we can predict how much mechanical degradation will occur inside the battery,\u201d says McMullin.\u00a0<\/p>\n\n\n\n<p>Then, he used dynamic light scattering and laser diffraction to determine the particles in the active material.&nbsp;&nbsp;<\/p>\n\n\n\n<p>\u201cKnowing the particle sizes and their distribution helps to understand and control the microstructure of the cathode. This also allows us to optimize the transport of lithium ions in the cathode, so we can get higher performing batteries\u201d he says.&nbsp;<\/p>\n\n\n\n<p>After the material is prepared, it was ready to be placed in cathodes within a battery cell to see which mixtures of material perform best. McMullin mixed the active material with an electrolyte, an electronic conductor, a polymer binder, and a solvent to create the composite cathode. He assembled cathodes with different ratios of materials and placed them in two batteries to see whether a stiffer electrolyte&nbsp;leads to more mechanical degradation.&nbsp;&nbsp;<\/p>\n\n\n\n<p>\u201cWe can measure the force changes during battery operation and estimate the stress the materials within the battery are experiencing, then correlate this to the mechanical properties of the electrolyte and, possibly, the particle size of the active material in the cathode,\u201d he says. \u201cIf the stress is higher in the electrode, it\u2019s more likely for the active material to degrade and crack. By testing these cells, I can design&nbsp;a cathode that uses the materials that perform the best in the batteries I create.\u201d&nbsp;<\/p>\n\n\n\n<p>McMullin completed his research under the guidance of Regina Garc\u00eda-M\u00e9ndez, assistant professor of materials science and engineering and core faculty of the Ralph O\u2019Connor Sustainable Energy Institute (ROSEI).&nbsp;<\/p>\n\n\n\n<p><\/p>\n\n\n\n<div class=\"wp-block-buttons is-content-justification-right is-layout-flex wp-container-core-buttons-is-layout-d445cf74 wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button\"><a class=\"wp-block-button__link has-medium-font-size has-custom-font-size wp-element-button\" href=\"https:\/\/engineering.jhu.edu\/materials\/news\/hard-core-batteries\/\">Read more here<\/a><\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>To make solid-state batteries tougher, a materials science and engineering student is rethinking what goes into the cathode\u2014and how it holds up under pressure<\/p>\n","protected":false},"author":47,"featured_media":12353,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_eb_attr":"","footnotes":""},"categories":[11,14],"tags":[],"class_list":["post-12335","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-design-day-news","category-news"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.7 - 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