What happened in China This story doesn't start in China. It starts with a collapse — and then it points directly at who is filling the vacuum. South Korean cathode materials company L&F disclosed that a supply agreement it had signed with Tesla in February 2023, originally valued at 3.83 trillion won (US$2.67 billion), had been revised down by roughly 99% to just 9.73 million won (US$6,700). As Jalopnik put it plainly: "The $2.9 billion contract signed in 2023 is now only worth $7,386." L&F cited a "change in supply quantity" without naming specific vehicle programs. The contract had covered high-nickel cathode materials — the premium-end of the cathode market — to be delivered from January 2024 through the end of 2025. Industry analysts were less coy: Tesla's 4680 battery cell program had hit a wall. Scaling a dry-electrode coating process proved far harder than Tesla had publicly suggested.…