When the use of Li metal may be risky…

Conventional electrochemical wisdom holds that the use of Lithium metal is risky. Indeed, even Li-ion batteries suffer major safety concerns associated with the growth of spiky Lithium dendrites resulting in an internal short circuit, followed by uncontrolled energy release. A common belief is that any rechargeable Lithium metal system would, sooner or later, generate uncontrolled dendritic Lithium.

In contrast, OXIS technology is inherently safe!

OXIS’s cells are UN38.3 approved and are safe to be transported by air. OXIS Li-S cell technology is inherently safe due both to the use of high flash point electrolytes and the formation of a Lithium sulfide layer on the lithium metal anode surface. The high flashpoint electrolyte increases the minimum temperature at which thermal runaway can occur and therefore results in OXIS’s cell having a high degree of thermal stability and good performance in several safety tests. The lithium sulfide layer passivates the lithium metal anode surface vastly reducing its reactivity, making the OXIS technology resilient to the most severe destructive tests such as the nail penetration test.

The Li-S battery of OXIS Energy can withstand the following tests with no adverse reaction.

Nail penetration

When punctured by an iron nail, OXIS Li-S cell continued to operate (voltage at 98%) with a temporary temperature variation of only +1.4⁰C.

Bullet penetration

A 5.56mm bullet was shot at a 10 meter range on a fully charged cell. The cell continued to operate at a reduced capacity and no fire or any noticeable temperature variation was observed.

Short circuit

OXIS patented cell can withstand short-circuit without catching fire. Meets UN38.3/IEC62133 specifications.

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Overcharge

When charged for 24 hours at a C/10 rate (0.16 A), no explosion or fire were observed and the cell reached a maximum temperature of 53⁰C. Meets IEC62133.

Crush

When subjected to a 13kN force, the cell did not disassemble and it only observed a temperature variation of 2⁰C. Meets UN38.3.

Shock

18 shocks with a 150gn acceleration (6ms) were applied to our test cell and there was no rupture, venting or mass loss. Meets UN38.3.