To use a battery to create a negative supply: Obtain a 9V transistor battery or a 4 or more cell AA alkaline battery pack or other source of 5V or more. (Or a mains "plugpack" power supply of 5V or more.) the -ve terminal will be at -V. eg a 9V battery will give -9V etc. +1 for "use a better op amp".
In a 9V battery, there are two terminals: anode for positive voltage and cathode for negative voltage. A 9V battery is a negative voltage source in the sense that negative voltage is an excess of electrons and a positive voltage is a deficiency of electrons.
Everyone might need a negative voltage power supply at some point. Before making a negative voltage circuit, it is essential to understand what negative voltage is. In a dual rail power supply, you can easily notice three outputs: positive, ground, and negative voltage.
Negative voltage is needed in some applications, such as in audio projects where speakers and piezo elements work great when applied positive and negative voltages. One of the other ways to produce a negative voltage is by taking advantage of the effect of capacitive coupling in capacitors.
When a circuit is designed for negative voltage supply, we can use a cathode as the negative voltage and an anode as ground. This can be seen with a multimeter. When checking the voltage of a battery with reverse polarity, you can observe the same amount of voltage but with a negative sign. A cathode can be used as a negative voltage source.
In a power supply, the ground is the reference voltage, which is approximately 0V. Negative voltage, on the other hand, is an excess of electrons, while positive voltage is a deficiency of electrons. A battery acts as a quick negative voltage source.