Research on environmental cost sharing mechanism of power battery supply chain considering blockchain technology investment

• This paper constructs a closed-loop supply chain cost-sharing model that incorporates blockchain and environmental costs. • It systematically compares three cost-sharing mechanisms: no cost-sharing, blockchain cost-sharing, and dual cost-sharing. • This research provides theoretical support for the design of fair and efficient cost-sharing contracts in power battery recycling. The rapid development of new energy vehicles has led to the concentrated retirement of power batteries, resulting in rising environmental governance costs in the recycling process and the absence of a unified accounting and sharing mechanism. While blockchain technology facilitates accurate accounting and rational allocation of environmental costs, it also introduces new cost-sharing pressures. Against the backdrop of both environmental and blockchain-related costs, achieving fair cost allocation among supply chain participants has become a pressing issue. To address this problem, this paper develops a Stackelberg game model and compares three cost-sharing mechanisms in a blockchain-enabled closed-loop supply chain: no cost sharing (NC), blockchain cost sharing (BC), and total cost sharing (TC). Based on numerical simulations with a market capacity of a = 10000 , production cost c = 10 , recycling prices c m = 3 and c r = 2 , and sensitivity parameters μ = 0.1 , β = 0.1 , λ = 0.5 , and k = 0.1 , the results show clear performance differences among the three mechanisms. Compared with the NC mechanism, the BC mechanism enhances pricing, traceability, and profitability; the TC mechanism further strengthens investment incentives, balances cost–benefit distribution, and improves overall system profit. These findings provide theoretical support and managerial insights for designing fair and efficient cost-sharing contracts, contributing to the sustainable development of power battery recycling supply chains.