Have no data on current source, but looks like future ones may be made by GM: https://insideevs.com/gm-teams-with-honda-to-develop-next-gen-advanced-battery/
Nikkei Asian Review reported on May 23rd: "Honda's current minicar and minivan lineup includes gasoline hybrid vehicles from a joint venture that it set up with Japanese battery makers Panasonic and GS Yuasa.. The Japanese carmaker said it intends to maintain those relationships." GS Yuasa's website says their Blue Energy Co., Ltd. is making the Li-Ion batteries for the Clarity Fuel Cell. Honda in America wrote: "The third generation Civic Hybrid, being introduced in the spring of 2011, will be the first Honda hybrid to utilize lithium-ion batteries, developed and produced by Blue Energy Co., Ltd., a join[t] venture effort by Honda and GS Yuasa." And jdonalds submitted in this forum post on December 16th: "To the best of my knowledge Blue Energy is supplying batteries for the Clarity. http://www.blue-energy.co.jp/en/products/index.html"