Buy EBL 4 Pack 9V 6F22 600mAh High Volume Lithium-ion Rechargeable 9 Volt Li- ion Batteries on FREE SHIPPING on qualified orders
Lithium-ion batteries can pose unique safety hazards since they contain a flammable electrolyte and may be kept pressurized. A battery cell charged too quickly could cause a short circuit, leading to explosions and fires.  Because of these risks, testing standards are more stringent than those for acid-electrolyte batteries, requiring both a broader range of test conditions and additional battery-specific tests.    There have been battery-related recalls by some companies, including the 2016 Samsung Galaxy Note 7 recall for battery fires.  
Lithium-ion batteries store chemical energy in reactive chemicals at the anodes and cathodes of a cell. Typically, anodes and cathodes exchange lithium (Li+) ions through a fluid electrolyte that passes through a porous separator which prevents direct contact between the anode and cathode. Such contact would lead to an internal short circuit and a potentially hazardous uncontrolled reaction. Electric current is usually carried by conductive collectors at the anodes and cathodes to and from the negative and positive terminals of the cell (respectively).
Additionally, Kentli batteries are lighter than Eneloop Pro. However, they are more expensive. A four pack of Eneloop Pros costs about $17, whereas a 4 pack of Kentli cells costs about $40.