ELECTRODE BINDER COMPOSITION, ELECTRODE COATING COMPOSITION, POWER STORAGE DEVICE ELECTRODE, AND POWER STORAGE DEVICE

Provided are an electrode binder composition that provides an electrode that exhibits high durability even when an active material that shows a large volume change is used, a power storage device electrode produced using the electrode binder composition, and a power storage device including the power storage device electrode. An electrode binder composition contains (A) one or more polymers selected from the group consisting of fluoropolymers, butadiene polymers, and thermoplastic elastomers, (B) a fibrous nanocarbon material having an average fiber diameter of 0.5 nm or more and 20 nm or less and a fiber length of 0.5 μm or more and 1 mm or less, (C) a cellulose material, (D) a nanocellulose fiber, and (E) water. The mass ratio between (A) and (B) is (A)/(B)=60/40 to 98/2.