Commercial lithium-ion (Li-ion) batteries based on graphite anodes are meeting their energy density limits. In order to satisfy the large market demands of smaller and lighter rechargeable batteries, high-capacity Li metal has been suggested as a replacement for low-specific-capacity graphite enabling higher energy density next-generation rechargeable Li metal batteries (LMBs), or all solid-state batteries (ASSBs) with Li metal as the anode to be realized. However, Li metal anodes suffer from dendritic problems, interfacial side reactions with liquid or solid electrolytes, significant cell volume change during battery cycling, and low Coulombic efficiency when used as an anode in different cell configurations. In order to overcome the above challenges, the main direction is to achieve a uniform Li deposition during Li plating and stripping, protecting lithium metal from Li dendrite formation. The construction of artificial protective layers before assembling cells has been shown to be very effective for LIBs and ASSBs. This idea could also be applied to Li metal batteries.
LLNL researchers have developed an artificial protective layer fabricated through a scalable and low-cost process, that can serve as a protective layer for improving the performance of any battery configuration using Li metal as an anode as well as the performance of anode-free Li-metal batteries or anode-free SSBs. This film can suppress Li-dendrite formation because of its mechanical properties. The invention helps solve a key challenge faced by anode-free solid-state lithium batteries by developing a protective polymer-based film coated directly onto the copper current collector and thus can pave the way to improving the cycle life of many lithium batteries.
Caption:The protective film can be used with (left) solid-state Li metal batteries (cathode-protective film-Li) and (right) anode-free solid state batteries (cathode-protective film-Cu).
- Improves in-situ formation of Li metal on to the current collector.
- Suppresses Li dendrite formation.
- Stabilizes the Li metal anode/electrolyte interface.
- Easily scaled synthesis
- Can be applied using several well-established coating methods such as spin coating or doctor blading.
- Lithium metal all solid-state batteries
- Anode free solid-state batteries
Current stage of technology development:
TRL ☐ 0-2 ☒ 3-5 ☐ 5-9
LLNL has filed for patent protection on this invention.