CATL has signed a cooperation framework agreement with the vessel division of China Oilfield Services Limited (COSL) to jointly develop electrified offshore support vessels, the company said in a March 28 statement.
The partnership will focus on battery-electric and hybrid propulsion systems tailored for offshore engineering and transport operations, with the aim of improving safety and reducing emissions in maritime oilfield logistics.
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The agreement builds on earlier retrofit projects involving the vessels Haiyang Shiyou 545 and Haiyang Shiyou 55, which were upgraded with LNG-battery hybrid systems. These vessels use load-shifting strategies to optimise performance by charging during low-demand periods and discharging at peak loads.
After a year in operation, the Haiyang Shiyou 545 reduced fuel consumption by around 170 tonnes and cut carbon emissions by more than 500 tonnes compared with conventional vessels, while also lowering engine runtime and improving operational stability, CATL said.
The new agreement signals CATL’s deeper expansion into maritime electrification, extending its battery expertise beyond road transport into offshore energy applications.
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The move comes amid a series of recent partnerships by CATL aimed at advancing electrification and decarbonisation across industries. In early March, the company signed a memorandum of understanding with Rio Tinto to explore cooperation on electrification strategies, circular supply chains and new commercial models linked to the energy transition.
CATL also reached a separate agreement with BMW Group to deepen collaboration on battery supply chain decarbonisation and cross-border data exchange, as part of broader industry efforts to reduce emissions.
The company’s growing influence is reflected in its market position. According to data from SNE Research, CATL and BYD together accounted for more than 55% of global electric vehicle battery installations in 2025.
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CATL alone remained the world’s largest EV battery supplier, with total installations reaching 464.7 GWh in 2025, up 35.7% from 342.5 GWh in 2024. Its global market share increased to 39.2%, making it the only battery manufacturer with a share exceeding 30%.
