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Breakthrough Solid State Battery - 900 Wh/L Samsung 
Samsung research was led by Yong-Gun Lee for an All-Solid-State-Battery (ASSBs). Their goal was to eliminate dendrites formation and increase coulombic efficiency.
To do that they sandwiched layers of Lithium Nickel-Cobalt-Manganese-Oxide (NMC for short) mixed with a Sulfide Solid Electrolytes (SSE, show formula on screen), on top of nanocomposite-layer of Silver-Carbon.
All of this is located in between a foil of Aluminum and Stainless steel as the current collectors.
The idea behind this was to remove lithium foil from the mix and have all lithium atoms part of the NMC and SSE. This approach diminishes the costs of the overall battery manufacturing since handling lithium usually needs an oxygen free environment due to its high reactivity.
This is important for a few reasons, in conventional lithium batteries, the anode comprised of lithium moves freely towards the positive electrode during discharge.
Dendrites are formed during the charging process when lithium moves back to its initial location thanks to the free movement enabled by liquid or gel electrolyte.
This is the main limiting factor of how much energy can be store in these batteries since to control this, the amount of lithium available in the system has to be caped, limiting the energy density.
History of batteries
Cost of production of lithium ion batteries