As you know the Boeing 787 has been grounded by caught fire on the Li-ion battery.
It looks like Japanese battery may have some issues on this incident:-(
You might reminded some laptop PCs caught fire by its Li-ion battery, few years before.
It is ironic to the restriction of Li-ion batteries for carry on baggage and air cargo.
Our copters will not fly without high power density Li-Po.
How do you treat your Li-Po battery and deposit after some failure ?