Rechargeable Type Battery Characteristic

1.Nickel Cadmium(NiCd) Battery:

         Nickel Cadmium Battery consists of positive and negative plate, separator, alkaline electrolyte, metal case and cover. The active material on the positive electrode is nickel hydroxide and the negative is cadmium. The electrochemical processes of the battery during charging and discharging are described below:

                                     Charge

    2Ni(OH)2 + Cd(OH)2 ⇌ 2NiOOH+ Cd+ 2H2O

                                     Discharge

        Nickel Cadmium Battery technology is well developed and mature. They are widely accepted in the application environment from military to commercial standard. The are popularly used in home appliance, power tool, two-ways radio & emergency/security system.

Characteristics:

1. Low cost : Good value for home appliance usage;

2. Long cycle life: if properly controlled in charging/discharging; it provides over 1000 cycle life.

3. Wide temperature range operation: -20 degc to +65 degC

4. Robust, Reliable & Maintenance free : Performance is still acceptable in tough operation condition i.e. Over-charging, deep discharge etc.

5. Long shelf life : High degree of capacity recoverbility in any state-of-charge.

Application:

Power tool,Telecommunication,Office Automatic equipment,Emergency lighting etc.

2.Nickel-Metal Hydride(NiMh) Battery:

      Nickel-Metal Hydride Battery consistes of positive and negative plate, separator, alkaline electrolyte, metal case and cover. The active material of the positive electrode is nickel hydroxide and the negative is hydrogen storage metal alloy. The electrochemical processes of the batteries during charging and the discharging are described below:

                                         Charge

                   2Ni(OH)2 + M ⇌ NiOOH + MH

                                        Discharge

      Nickel-Metal Hydride Battery is made by environmental friendly material. They have higher energy density and replace some Nickel Cadmium Battery in some applications, such as toy, power tool and telecommunication equipments etc.

Characteristics:

1. High Energy density:30%-50% Higher capacity than standard NiCd battery.

2. High Power: Discharge rate can be as high as Nicd but loner operating time.

3. Nearly no 'memory effect': Periodical fully discharging before re-charging is less frequent.

4. Green Power: No material hazardous to environment, no special restriction on way of disposal.

Application:

Toy,Power tool,Telecommunication etc.

3. Lithium Ion (Li-ion) Battery:

     Lithium-ion battery consist positive and negative plate, separator, alkaline electrolyte, metal case and cover. The active material of the positive electrode is Lithum Metal oxide and the negative is represented by highly crystalline carbon material. The electrochemical processes of the batteries during charging and the discharging are described below:

                                    Charge

                        LiMO2 + C ⇌ Li1-xCoO2 + Lix C

                                   Discharge

        Lithium-ion battery is typically twice the capacity of standard NiCd battery. They are widely used in portable electronic device such as Notebook type computer, mobile phone, digital camera etc due to high energy and compact characteristic. Power device application is growing up due to the greatly improvement in discharging capability in recent years.

Characteristics:

1. Highest Energy Density vs NiCd/Mh type: Capacity upgrade potential still on the way.

2. Low self-discharge rate: High efficiency in usable capacity.

3. No memory effect: no need of periodic fully discharge to maintain cell capacity.

4. High operating voltage: 3.6V equivalent to 3 cells of NiCd/Mh type connected in series, simplifying cell assembling and single cell operation is possible in most modern electronic appliances.

5. Light weight: Good for such portable equipment as mobile phone, DSC, PDA etc.

6. Green Power: No material hazardous to environment, no special restriction on way of disposal.

Application:

Mobile phone,Notebook computer,Digital camera,Camcorder ,etc.

4. Lithium Polymer (Li-polymer) Battery:

         Lithium-polymer battery consist positive and negative plate, solid electrolyte(separator). The active material of the positive electrode is Lithium Metal oxide and the negative is represented by highly crystalline carbon material. The electrochemical processes of the batteries during charging and the discharging are described below:

                                   Charge

                    LiMO2 + C ⇌ Li1-xCoO2 + Lix C

                                   Discharge

        Lithium-polymer battery is widely used in mobile phones, PDA, MP3/MP4 players etc, where, 'lightness' rather than 'power' is the major concern.

Characteristics:

1. Improved Safety: 'Gelled Solid State Electrolyte' reduce the risk of Electrolyte leakage.

2. High Operating Voltage: 3.6V per cell same as Liion battery.

3. Low profile: thickness as thin as a credit card is possible.

4. Light weight: Metal case is not needed due to low risk of electrolyte leakage. Good for small portable electronic device.

5. Green Power: No material hazardous to environment, no special restriction on way of disposal.

Application:

MP3/MP4 player,PDA, Bluetooth Headset etc.