Only gross negligence is needed per the statute, not intent. Read it for yourself. James Comey essentially rewrote the meaning of the statute when he let Hillary skate, but James Comey does not establish legal precedent changes of written law.
But. let's set aside this point and just for a moment consider that the law did require intent. Biden would have to claim that these documents which only he could remove from his office upon leaving were distributed to his Think Tank, his personal library, his garage next to his favorite car, and another page of classified material in a different room of his personal home without inent which is ludicrous. But the law DOES NOT mention INTENT. yet even so, Biden clearly had intent. He also cannot claim ignorance, given his comments about Trump.
And we haven't discussed the requiremnt by law of timely notification when a breach is found....we now know that they knew back on Nov 1rst, yet only notified much later (unless the Garland DOJ is part of this cover up too, but I am not going believe that at this point).
Link: https://www.law.cornell.edu/uscode/text/18/793