Performance of the Sony Lithium-Ion Rechargeable Battery

Sony lithium-ion cells type 20500 were tested and evaluated at different temperatures, discharge rates from C2 to 3C, and with different charge voltage cutoffs. The capacity was typical 0.8 Ah at the C2 rate at 25 deg C when charged to 4.1-volt cutoff. An energy density of 70 Whkg and 400 or more cycles was demonstrated. Charging to 4.25 volts and higher cutoffs was tested without a safety problem. The Sony charger provided a constant potential charge at 8.2 volts 4.1 voltscell. It replaces 90 of capacity within one hour and it shut off the charging after 2-12 hours. Lithium-ion batteries, Rechargeable batteries, Electrodes, Electrolytes, Organic, Charging.