8. 24M’s semi solid battery

A 24M cell prototype with semisolid cathode.
The 24M semisolid battery concept

Semisolid, high rate battery patent

24M website

Seminal paper on semisolid concept from Chiang with original concept

Recent article on 24M attracting investment

Yet Ming Chiang MIT group website

Car OEMs are scrambling to acquire new battery technology in a wide effort to push energy densities and lower costs. 24M is one of several start-ups which has garnered attention and $$$$ from investors touting a semisolid battery concept with high capacity and high rate. In this podcast I explain what’s in the “secret sauce” by discussing their patents.

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7. Cathode chit chat. NMC what?

My guest, Rajesh Mekkat discusses commercial cathodes for lithium ion batteries

Scanning electron micrograph of a NCM622 cathode cross section

Cathodes are positive electrodes in batteries and are responsible for the high voltage. In this podcast I discuss with Rajesh Mekkat the intricacies of commercial lithium ion cathodes preferred by electric automakers such as NCM, LMO and lithium rich cathodes. Rajesh has been a cathode research engineer for Renault-Nissan in various leadership positions for close to 10 years. Recently, he continues his cathode work in China, at the largest SUV OEM in the country: Great Wall Motor. You can view his LinkedIn profile here. Many safety and energy density features are governed by the cathode.

Today’s guest and cathode specialist: Rajesh Mekkat

6. Lithium metal anodes (fast as snails?!)

Faster Li plating through LLZO solid electrolytes. Latest from the Sakamoto group.
LLZO solid electrolyte pelltet. Easy to work with in small areas. But how can large, thin sheets be made for commercial applications?

Paper link: https://www.sciencedirect.com/science/article/abs/pii/S0378775318306529

Sakamoto group page: https://sakamoto.engin.umich.edu/people/

News article: https://news.umich.edu/battery-breakthrough-doubling-performance-with-lithium-metal-that-doesnt-catch-fire/

Plating lithium metal anodes through inorganic solid electrolytes is challenging and slow due to proliferation of dendrites along the grain boundary where ionic conductivity is higher. Sakamoto’s group shares evidence of rate improvements without dendritic growth with LLZO solid electrolytes. 

5. The secret ionic material of Ionic Materials

 

Patent 1

Patent 2

Mike Zimmerman’s Tufts webpage

Ionic Materials webpage

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Superior conductivity of the solid electrolyte @ Ionic Materials (picture from the company’s website)

The brain child of liquid crystal polymer guru Mike Zimmerman, Ionic Materials has attracted a lot of recent investment from car OEMs and battery companies alike. Renault, Nissan, Mitsubishi, Volta and A123 are a few of the publicized investors. The main draw is their solid polymer electrolyte which self extinguishes if set on fire and has HIGHER conductivity than commercial liquid electrolytes even at temperatures as low as -20C. In this podcast i dissect (the only) two patents from this company and discuss their “secret” solid electrolyte composition.

4. Sion Power’s better Li-metal anodes by force!

 

Link to patent US20180269520

Link to Sion Power’s Li-metal anode commercial cell

Sion Power has been a leader in batteries with lithium metal for more than 20 years. Traditionally championing lithium-sulfur batteries, it has recently expanded into high energy density batteries with lithium metal and traditional high voltage cathodes such as NMC622/811, etc. It’s Licerion product offers a 20Ah pouch cell,  500 Wh/kg, 1000 Wh/l with an impressive EOL of 80% after 500 cycles at C/3. In this podcast i discuss its 2018 patent on the importance of (anisotropic) pressure applied to cells with lithium metal anodes. Enjoy!

3. 3D lithium metal anode from Prologium

 

Patent

Prologium website

A lithium metal electrode and its related lithium metal battery is disclosed in the present invention. The lithium metal electrode comprises a current collector, a lithium metal layer, an insulation frame, a porous electrical insulation layer and an ionic diffusion layer. The current collector has at least a well. The lithium metal layer is disposed on the bottom surface of the well. The insulation frame is disposed alone the opening of the well. The insulation frame extends radially outward the opening to cover a top surface of the current collector partially and extends vertically toward the inner sidewall of the well. The lithium dendrites will mostly plate in the well and will not plate upwards due to the inhibition layer. Hence, the lithium dendrites will not penetrate through the electrical insulator so that the safety of the lithium metal battery can be improved greatly.

2. New sulfur cathode from Nazar’s group

 

Linda Nazar’s group page

Paper link

The lithium-sulfur battery, despite possessing high theoretical specific energy, faces practical challenges of polysulfide shuttling and low cell-level energy density and hence requires significant functional advances over porous carbon for the cathode host. Here we report the lightweight superconductor MgB 2—whose average mass/atom is comparable with carbon—as a metallic sulfur host that fulfills both electron conduction and polysulfide immobilization properties. We show by means of first-principles calculations that borides are unique in that both B- and Mg-terminated surfaces bond exclusively with the S x 2− anions (not Li +), and hence enhance electron transfer to the active S x 2− ions. The surface-mediated polysulfide redox behavior results in a much higher exchange current in comparison with MgO and carbon. By sandwiching MgB 2 nanoparticles between graphene nanosheets to form a high-surface-area composite structure, we demonstrate sulfur cathodes that achieve stable cycling at a high sulfur loading of 9.3 mg cm −2.