batch_size in neural network
I guess you have a confusion here. The None part represents the number of samples.
For example if you have a neural network with architecture 100-50-10, it means that you have

(None,100) : input layer shape
(100,50) : shape for weights connecting input to hidden layer
(None,50): shape for hidden layer given by (None,100)*(100,50) matrix multiplication
(None,50): shape after nonlinearity application.
(50,10):  shape for the shape matrix between hidden and output layer
(None,10) : output layer shape (None,50)*(50,10) matrix multiplication

So if youre feeding a single input sample the shapes would be:
(1,100)[Input] =&gt; (1,100)(100,50) = (1,50)[Hidden Layer] =&gt; (1,50)*(50,10)=(1,10)[Output Layer]